U.S. patent number 10,619,019 [Application Number 15/533,398] was granted by the patent office on 2020-04-14 for acrylic polyvinyl acetal films, composition, and heat bondable articles.
This patent grant is currently assigned to 3M Innovative Properties Company. The grantee listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Mary M. Caruso Dailey, Jonathan E. Janoski, Corinne E. Lipscomb, Anthony F. Schultz.
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United States Patent |
10,619,019 |
Lipscomb , et al. |
April 14, 2020 |
Acrylic polyvinyl acetal films, composition, and heat bondable
articles
Abstract
A film is described comprises a (meth)acrylic polymer and a
polyvinyl acetal (e.g. butyral) resin. The film has a tensile
elastic modulus of at least 1 MPa at 25.degree. C. and 1 hertz and
a glass transition temperature (i.e. Tg) less than 30 C. The film
typically comprises photoinitiator as a result of the method by
which the film was made. In one embodiment, the film is heat
bondable and further comprising a backing.
Inventors: |
Lipscomb; Corinne E. (St. Paul,
MN), Caruso Dailey; Mary M. (Maplewood, MN), Janoski;
Jonathan E. (Woodbury, MN), Schultz; Anthony F. (Forest
Lake, MN) |
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
|
|
Assignee: |
3M Innovative Properties
Company (St. Paul, MN)
|
Family
ID: |
55221496 |
Appl.
No.: |
15/533,398 |
Filed: |
December 7, 2015 |
PCT
Filed: |
December 07, 2015 |
PCT No.: |
PCT/US2015/064219 |
371(c)(1),(2),(4) Date: |
June 06, 2017 |
PCT
Pub. No.: |
WO2016/094280 |
PCT
Pub. Date: |
June 16, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170362399 A1 |
Dec 21, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62088963 |
Dec 8, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08J
5/18 (20130101); B32B 27/304 (20130101); B32B
27/306 (20130101); B32B 27/00 (20130101); B32B
27/308 (20130101); B32B 27/08 (20130101); B32B
27/30 (20130101); B32B 2250/246 (20130101); B32B
2307/546 (20130101); B32B 2307/54 (20130101); C08J
2429/14 (20130101); B32B 2255/26 (20130101); B32B
2307/732 (20130101); B32B 2307/31 (20130101); C08J
2333/08 (20130101); B32B 2255/10 (20130101) |
Current International
Class: |
C08J
5/18 (20060101); B32B 27/08 (20060101); B32B
27/00 (20060101); B32B 27/30 (20060101) |
References Cited
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Primary Examiner: Jones; Robert S
Attorney, Agent or Firm: Fischer; Carolyn A.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national stage filing under 35 U.S.C. 371 of
PCT/US2015/064219, filed Dec. 7, 2015, which claims the benefit of
U.S. Provisional Application No. 62/088,963, filed Dec. 8, 2014,
the disclosure of which is incorporated by reference in its/their
entirety herein.
Claims
What is claimed is:
1. A film comprising: (meth)acrylic polymer and 5 to 20 wt. %
polyvinyl acetal resin comprising polymerized units having the
following formula ##STR00008## wherein R.sub.1 is hydrogen or a
C1-C7 alkyl group; wherein the film has a tensile elastic modulus
of at least 1 MPa at 25 C and 1 hertz and a Tg less than 30.degree.
C.
2. The film of claim 1 wherein the film comprises at least 25 wt-%
and no greater than 85 wt. % of polymerized units of monofunctional
alkyl (meth)acrylate monomer having a Tg of less than 0.degree.
C.
3. The film of claim 2 wherein the monofunctional alkyl
(meth)acrylate monomer has a Tg of less than -10.degree. C.
4. The film of claim 1 wherein the film comprises a bio-based
content of at least 25% of the total carbon content.
5. The film of claim 1 wherein the film comprises polymerized units
of an alkyl (meth)acrylate monomer having an alkyl group with 8
carbon atoms.
6. The film of claim 1 wherein the film further comprises up to 20
wt-% of polymerized units of a monofunctional alkyl (meth)acrylate
monomer having a Tg greater than 40.degree. C.
7. The film of claim 1 wherein the film further comprises at least
5 wt-% and no greater than 65 wt-% of polymerized units of polar
monomers.
8. The film of claim 7 wherein polar monomers are selected from
acid-functional, hydroxyl functional monomers, nitrogen-containing
monomers, and combinations thereof.
9. The film of claim 1 wherein the film comprises polyvinyl
butyral.
10. The film of claim 1 wherein the polyvinyl acetal resin has a
polyvinyl alcohol content ranging from 10 to 30 wt-%.
11. The film of claim 1 wherein the polyvinyl acetal resin has a
glass transition temperature ranging from 60.degree. C. to
75.degree. C.
12. The film of claim 1 wherein the polyacetal resin has an average
molecular weight (Mw) ranging from 10,000 g/mole to 100,000
g/mole.
13. The film of claim 1 wherein the film further comprises
polymerized units of a multifunctional crosslinker wherein the
crosslinker is a traizine crosslinker or comprises functional
groups selected from (meth)acrylate, alkenyl, and hydroxyl-reactive
groups.
14. The film of claim 1 wherein the film further comprises
additives in an amount no greater than 25 wt-%.
15. The film composition of claim 1 wherein the film composition
comprises photoinitiator.
16. The film composition of claim 1 wherein the film comprises no
greater than 10 wt-% of polymerized units of methacrylate
monomers.
17. The film composition of claim 1 wherein the (meth)acrylic
polymer is a random copolymer.
18. The film of claim 1 wherein the film is a monolithic film.
19. The film of claim 1 wherein the film is a film layer of a
multilayer film.
20. The film of claim 1 wherein the film exhibits a single Tg as
measured by Differential Scanning calorimetry.
21. The film of claim 1 wherein the film is heat bondable at a
temperature from 50 to 150.degree. C.
Description
SUMMARY
In one embodiment, a film is described. The film comprises a
(meth)acrylic polymer and a polyvinyl acetal resin. The polyvinyl
acetal resin comprises polymerized units having the formula
##STR00001## wherein R.sub.1 is hydrogen or a C1-C7 alkyl group.
The film has a tensile elastic modulus of at least 1 MPa at
25.degree. C. and 1 hertz and a glass transition temperature (i.e.
Tg) less than 30.degree. C. The film typically comprises
photoinitiator as a result of the method by which the film was
made. The film may be a monolithic film or a (e.g. exterior) layer
of a multilayer film.
In another embodiment, a method of making a film is described. The
method comprises providing a composition comprising polyvinyl
acetal resin and free-radically polymerizable solvent monomer. The
method comprises applying the composition to a substrate (e.g.
release liner or substrate); polymerizing the solvent monomer; and
optionally crosslinking the composition thereby forming a film or
film layer. The polyvinyl acetal resin and types and amounts of
free-radically polymerizable solvent monomer are selected such that
the cured composition has a tensile elastic modulus of at least 1
MPa at 25.degree. C. and 1 hertz and a Tg less than 30.degree.
C.
In yet another embodiment, a composition is described comprising a
(meth)acrylic polymer and a polyvinyl acetal resin. The composition
preferably has a tensile elastic modulus of at least 1 MPa at
25.degree. C. and 1 hertz and a Tg less than 30.degree. C.
In some embodiments, the film and/or (e.g. radiation) polymerized
and optionally cured composition exhibits a suitable balance of
properties such that it can be utilized as a replacement for
polyvinyl chloride films or other types of (e.g. flexible) films.
In other embodiments, the film and/or (e.g. radiation) cured
composition exhibits a suitable balance of properties such that it
can be utilized as a heat bondable film.
DETAILED DESCRIPTION
Presently described are films and compositions comprising a
(meth)acrylic polymer and polyvinyl acetal resin, as well as
methods of making. The composition is preferably prepared by
dissolving polyvinyl acetal resin in a free-radically polymerizable
solvent monomer. The solvent monomer is preferably polymerized by
exposure to (e.g. ultraviolet) radiation.
The "Dahlquist Criterion for Tack" is widely recognized as a
necessary condition of a pressure sensitive adhesives (PSA). It
states that a PSA has a shear storage modulus (G') of less than
3.times.10.sup.6 dyne/cm.sup.2 (0.3 MPa) at approximately room
temperature (25.degree. C.) and a frequency of 1 Hertz (Pocius,
Adhesion and Adhesive Technology 3.sup.rd Ed., 2012, p. 288).
A shear storage modulus can be converted to a tensile storage
modulus using the following equation: E'=2G'(r+1), where r is
Poisson's ratio for the relevant material. Using this equation and
given that Poisson's ratio of elastomers and PSAs is close to 0.5,
the Dahlquist Criterion expressed as a tensile storage modulus (E')
is less than 0.9 MPa (9.times.10.sup.6 dyne/cm.sup.2).
The film and (e.g. radiation) cured composition described herein
generally has a tensile storage modulus (E') at 25.degree. C. of
greater than 9.times.10.sup.6 dynes/cm.sup.2 (0.9 MPa) at 1 hertz
as can be measure by dynamic mechanical analysis (as determined by
the test method described in the examples). The tensile storage
modulus (E') at 25.degree. C. and 1 Hertz is usually greater than
5.times.10.sup.7 (5 MPa) dynes/cm.sup.2, and in some embodiments at
least 1.times.10.sup.8 dynes/cm.sup.2 (10 MPa), 5.times.10.sup.8
dynes/cm.sup.2 (50 MPa). In some embodiments, the tensile storage
modulus (E') at 25.degree. C. and 1 Hertz is at least
1.times.10.sup.9 dynes/cm.sup.2, 5.times.10.sup.9 dynes/cm.sup.2,
or 1.times.10.sup.10 dynes/cm.sup.2 (i.e. 1000 MPa) at 1 Hertz.
Thus, the film and composition is not a pressure sensitive adhesive
in accordance with the Dahlquist criteria.
The film and composition comprises polymerized units of one or more
(meth)acrylate ester monomers derived from a (e.g. non-tertiary)
alcohol containing 1 to 14 carbon atoms and preferably an average
of 4 to 12 carbon atoms
Examples of monomers include the esters of either acrylic acid or
methacrylic acid with non-tertiary alcohols such as ethanol,
1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol,
2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol,
1-hexanol, 2-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol,
2-ethyl-1-butanol; 3,5,5-trimethyl-1-hexanol, 3-heptanol,
1-octanol, 2-octanol, isooctylalcohol, 2-ethyl-1-hexanol,
1-decanol, 2-propylheptanol, 1-dodecanol, 1-tridecanol,
1-tetradecanol, and the like.
The film and composition comprises polymerized units of one or more
low Tg (meth)acrylate monomers, i.e. a (meth)acrylate monomer when
reacted to form a homopolymer has a T.sub.g no greater than
0.degree. C. In some embodiments, the low Tg monomer has a T.sub.g
no greater than -5.degree. C., or no greater than -10.degree. C.
The Tg of these homopolymers is often greater than or equal to
-80.degree. C., greater than or equal to -70.degree. C., greater
than or equal to -60.degree. C., greater than or equal to
-50.degree. C., or greater than or equal to -40.degree. C.
The low Tg monomer may have the formula
H.sub.2C.dbd.CR.sup.1C(O)OR.sup.8 wherein R.sup.1 is H or methyl
and R.sup.8 is an alkyl with 1 to 22 carbons or a heteroalkyl with
2 to 20 carbons and 1 to 6 heteroatoms selected from oxygen or
sulfur. The alkyl or heteroalkyl group can be linear, branched,
cyclic, or a combination thereof.
Exemplary low Tg monomers include for example ethyl acrylate,
n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl
acrylate, n-pentyl acrylate, isoamyl acrylate, n-hexyl acrylate,
2-methylbutyl acrylate, 2-ethylhexyl acrylate, 4-methyl-2-pentyl
acrylate, n-octyl acrylate, 2-octyl acrylate, isooctyl acrylate
(Tg=-70.degree. C.), isononyl acrylate, decyl acrylate, isodecyl
acrylate, lauryl acrylate, isotridecyl acrylate, octadecyl
acrylate, and dodecyl acrylate.
Low Tg heteroalkyl acrylate monomers include, but are not limited
to, 2-methoxyethyl acrylate and 2-ethoxyethyl acrylate.
In some embodiments, the film and composition comprises polymerized
units of at least one low Tg monomer(s) having an alkyl group with
6 to 20 carbon atoms. In some embodiments, the low Tg monomer has
an alkyl group with 7 or 8 carbon atoms. Exemplary monomers
include, but are not limited to, 2-ethylhexyl (meth)acrylate,
isooctyl (meth)acrylate, n-octyl (meth)acrylate, 2-octyl
(meth)acrylate, isodecyl (meth)acrylate, and lauryl
(meth)acrylate.
In some embodiments, the monomer is an ester of (meth)acrylic acid
with an alcohol derived from a renewable source. A suitable
technique for determining whether a material is derived from a
renewable resource is through .sup.14C analysis according to ASTM
D6866-10, as described in US2012/0288692. The application of ASTM
D6866-10 to derive a "bio-based content" is built on the same
concepts as radiocarbon dating, but without use of the age
equations. The analysis is performed by deriving a ratio of the
amount of organic radiocarbon (.sup.14C) in an unknown sample to
that of a modern reference standard. The ratio is reported as a
percentage with the units "pMC" (percent modern carbon).
One suitable monomer derived from a renewable source is 2-octyl
(meth)acrylate, as can be prepared by conventional techniques from
2-octanol and (meth)acryloyl derivatives such as esters, acids and
acyl halides. The 2-octanol may be prepared by treatment of
ricinoleic acid, derived from castor oil, (or ester or acyl halide
thereof) with sodium hydroxide, followed by distillation from the
co-product sebacic acid. Other (meth)acrylate ester monomers that
can be renewable are those derived from ethanol and 2-methyl
butanol. In some embodiments, the film and composition comprises a
bio-based content of at least 10, 15, 20, 25, 30, 35, 40, 45, 50,
55 or 60 wt-% using ASTM D6866-10, method B.
In some embodiments, the film and composition typically comprises
at least 25 or 30 wt-% of polymerized units of monofunctional alkyl
(meth)acrylate monomer having a Tg of less than 0.degree. C., based
on the total weight of the polymerized units (i.e. excluding
inorganic filler or other additives). In this embodiment, the film
and composition typically comprises no greater than 60, 55, 50, 45
or 40 wt-% of polymerized units of monofunctional alkyl
(meth)acrylate monomer having a Tg of less than 0.degree. C., based
on the total weight of the polymerized units.
In other embodiments, the films and compositions typically
comprises at least 35, 40, 45, or 50 wt-% of polymerized units of
monofunctional alkyl (meth)acrylate monomer having a Tg of less
than 0.degree. C., based on the total weight of the polymerized
units (i.e. excluding inorganic filler or other additives). As used
herein, wt-% of polymerized units refers to the wt-% based on the
total weight of the (meth)acrylic polymer, polyvinyl acetal (e.g.
butyral) resin, and crosslinker when present. The heat bondable
films and compositions preferably comprise at least 50, 55, 60, 65,
70 or 75 wt-% of polymerized units of monofunctional alkyl
(meth)acrylate monomer having a Tg of less than 0.degree. C., based
on the total weight of the polymerized units In some embodiments,
the film and composition typically comprises no greater than 85
wt-% of polymerized units of monofunctional alkyl (meth)acrylate
monomer having a Tg of less than 0.degree. C., based on the total
weight of the polymerized units.
When the film or composition is free of unpolymerized components
such an inorganic filler and additives, the wt-% of specified
polymerized units is approximately the same as the wt-% of such
polymerized units present in the total composition. However, when
the composition comprises unpolymerized components, such as
inorganic filler or other unpolymerizable additive the total
composition can comprise substantially less polymerized units. In
some embodiments the total amount of unpolymerizable additives may
range up to 25 wt-%. Thus, in the case of films and composition
comprising such unpolymerizable additives the concentration of
specified polymerized units can be as much as 5, 10, 15, 20, 25
wt-% less, depending on the total concentration of such additives.
For example, when the film or composition comprises 20 wt-%
inorganic filler, the concentration of low Tg monofunctional alkyl
(meth)acrylate monomer may be 20% less of the concentration
limitations described herein.
In some embodiments, the film and composition generally comprise at
least one (e.g. non-polar) high Tg monomer, i.e. a (meth)acrylate
monomer when reacted to form a homopolymer has a Tg greater than
0.degree. C. The high Tg monomer more typically has a Tg greater
than 5.degree. C., 10.degree. C., 15.degree. C., 20.degree. C.,
25.degree. C., 30.degree. C., 35.degree. C., or 40.degree. C.
In some embodiments, the film and composition comprises at least
one high Tg monofunctional alkyl (meth)acrylate monomers including
for example, t-butyl acrylate, methyl methacrylate, ethyl
methacrylate, isopropyl methacrylate, n-butyl methacrylate,
isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate,
stearyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate,
isobornyl acrylate, isobornyl methacrylate, norbornyl
(meth)acrylate, benzyl methacrylate, 3,3,5 trimethylcyclohexyl
acrylate, cyclohexyl acrylate, N-octyl acrylamide, and propyl
methacrylate or combinations.
In some embodiments, the film and composition comprises at least 1,
2, or 3 wt-% up to 35 or 40 wt-% of polymerized units of a
monofunctional alkyl (meth)acrylate monomer having a Tg greater
than 40.degree. C., 50.degree. C., 60.degree. C., 70.degree. C., or
80.degree. C. based on the total weight of the polymerized units
(i.e. excluding inorganic filler or other additives). In some
embodiments, the film and composition comprises no greater than 30,
25, 20, or 10 wt-% of polymerized units of high Tg monofunctional
alkyl (meth)acrylate monomer. In other embodiments, such as heat
bondable films, the film and composition may comprise less than 5,
4, 3, 2, 1, 0.5, 0.1 wt-% or is free of polymerized units of high
Tg monofunctional alkyl (meth)acrylate monomer.
The Tg of the homopolymer of various monomers is known and is
reported in various handbooks. The following table sets forth the
Tg of some illustrative monomers as reported (unless specified
otherwise) in Polymer Handbook, 4.sup.th edition, edited by J.
Brandrup, E. H. Immergut, and E. A. Grulke, associate editors A.
Abe and D. R. Bloch, J. Wiley and Sons, New York, 1999.
Glass Transition Temperature (Tg) of the Homopolymer of
Monomers
TABLE-US-00001 Tg, .degree. C. Tg, .degree. C. Methyl 105
Methacrylic acid 223 methacrylate Isobutyl methacrylate 53
2-hydroxyethyl acrylate 4 (b) Hexyl methacrylate -5 2-hydroxyethyl
methacrylate 85 Methyl acrylate 10 N-vinyl carbazole 212 (a) Butyl
acrylate -54 N,N-dimethyl acrylamide 89 2-octyl acrylate -45
N-vinyl pyrrolidone 54 2-ethylhexyl -50 N,N-Dimethylamino -39 (a)
acrylate ethyl acrylate Isobornyl acrylate 94 N,N-Dimethylamino 19
ethyl methacrylate Acrylic acid 106 (a) I. Sideridou-Karayannidou
and G. Seretoudi, Polymer, Vol. 40, Issue 17, 1999, pp. 4915-4922.
(b) B. Aran, M. Sankir, E. Vargun, N. D. Sankir, and A. Usanmaz;
Journal of Applied Polymer Science, Wiley Periodicals, Inc., A
Wiley Company, 2010, Vol. 116, pp. 628-635
In some embodiments, the film and composition further comprises at
least 10, 15 or 20 wt-% and no greater than 65, 60, 55, 50 or 45
wt-% of polymerized units of polar monomers. In other embodiments,
such as heat bondable films, the film and composition may comprise
lower concentrations of polar monomers, ranging from about 1, 2, 3,
4, or 5 wt-% up to about 15 or 20 wt-% of the polymerized units.
Such polar monomers generally aid in compatibilizing the polyvinyl
acetal (e.g. butyral) resin with the high and low Tg alkyl
(meth)acrylate solvent monomers. The polar monomer typically have a
Tg greater than 0.degree. C., yet the Tg may be less than the high
Tg monofunctional alkyl (meth)acrylate monomer when high Tg
monofunctional alkyl (meth)acrylate monomer is present.
Representative polar monomers include for example acid-functional
monomers, hydroxyl functional monomers, nitrogen-containing
monomers, and combinations thereof.
In some embodiments, the film and composition comprises polymerized
units of an acid functional monomer (a subset of high Tg monomers),
where the acid functional group may be an acid per se, such as a
carboxylic acid, or a portion may be salt thereof, such as an
alkali metal carboxylate. Useful acid functional monomers include,
but are not limited to, those selected from ethylenically
unsaturated carboxylic acids, ethylenically unsaturated sulfonic
acids, ethylenically unsaturated phosphonic acids, and mixtures
thereof. Examples of such compounds include those selected from
acrylic acid, methacrylic acid, itaconic acid, fumaric acid,
crotonic acid, citraconic acid, maleic acid, oleic acid,
.beta.-carboxyethyl (meth)acrylate, 2-sulfoethyl methacrylate,
styrene sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid,
vinylphosphonic acid, and mixtures thereof.
Due to their availability, acid functional monomers are generally
selected from ethylenically unsaturated carboxylic acids, i.e.
(meth)acrylic acids. When even stronger acids are desired, acidic
monomers include the ethylenically unsaturated sulfonic acids and
ethylenically unsaturated phosphonic acids. In some embodiments,
the film and composition comprises 0.5 up to 15, 20 or 25 wt-% of
polymerized units of acid functional monomers, such as acrylic
acid. In some embodiments, the film and composition comprises at
least 1, 2, 3, 4, or 5 wt-% of polymerized units of acid-functional
monomers up to about 15 or 20 wt-% of the polymerized units. In
other embodiments, the film and composition comprises less than
1.0, 0.5, 0.1 wt-% or is free of polymerized units of
acid-functional monomers.
In some embodiments, the film and composition comprises
non-acid-functional polar monomer.
One class of non-acid-functional polar monomers includes
nitrogen-containing monomers. Representative examples include
N-vinylpyrrolidone; N-vinylcaprolactam; acrylamide; mono- or
di-N-alkyl substituted acrylamide; t-butyl acrylamide;
dimethylaminoethyl acrylamide; and N-octyl acrylamide. In some
embodiments, the film and composition comprises at least 0.5, 1, 2,
3, 4, or 5 wt-% of polymerized units of nitrogen-containing
monomers and typically no greater than 25 or 30 wt-%. In other
embodiments, the film and composition comprises less than 1.0, 0.5,
0.1 wt-% or is free of polymerized units of nitrogen-containing
monomers.
Another class of non-acid-functional polar monomers includes
alkoxy-functional (meth)acrylate monomers. Representative examples
2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethoxyethyl
(meth)acrylate, 2-hydroxyethyl (meth)acrylate,
2-(methoxyethoxy)ethyl (meth)acrylate, 2-methoxyethyl methacrylate,
and polyethylene glycol mono(meth)acrylates.
In some embodiments, the film and composition comprises at least
0.5, 1, 2, 3, 4, or 5 wt-% of polymerized units of
alkoxy-functional (meth)acrylate monomers and typically no greater
than 30 or 35 wt-%. In other embodiments, the film and composition
comprises less than 1.0, 0.5, 0.1 wt-% or is free of polymerized
units of alkoxy-functional (meth)acrylate monomers.
Preferred polar monomers can include acrylic acid, 2-hydroxyethyl
(meth)acrylate; N,N-dimethyl acrylamide and N-vinylpyrrolidinone.
In some embodiments, the film and composition comprises polymerized
units of polar monomer in an amount of at least 10, 15 or 20 wt-%
and typically no greater than 65, 60, 55, 50 or 45 wt-%.
The film and composition may optionally comprise vinyl monomers
including vinyl esters (e.g., vinyl acetate and vinyl propionate),
styrene, substituted styrene (e.g., .alpha.-methyl styrene), vinyl
halide, and mixtures thereof. As used herein vinyl monomers are
exclusive of polar monomers. In some embodiments, the film and
composition comprises at least 0.5, 1, 2, 3, 4, or 5 wt-% and
typically no greater than 10 wt-% of polymerized units of vinyl
monomers. In other embodiments, the film and composition comprises
less than 1.0, 0.5, 0.1 wt-% or is free of polymerized units of
vinyl monomers.
In some favored embodiments, the polymerized units of the
(meth)acrylic polymer contain aliphatic groups and lack aromatic
moieties.
In typical embodiments, the solvents monomer(s) are polymerized to
form a random (meth)acrylic polymer copolymer.
The polyvinyl acetal resin utilized in the present invention is
obtained, for example, by reacting polyvinyl alcohol with aldehyde,
as known in the art.
Polyvinyl alcohol resins are not limited by the production method.
For example, those produced by saponifying polyvinyl acetate and
the like with alkali, acid, ammonia water, and the like, can be
used. Polyvinyl alcohol resins may be either completely saponified
or partially saponified. It is preferable to use those having a
saponification degree of 80 mol % or more.
The polyvinyl alcohol resins may be used singly or in combination
of two or more.
Aldehydes used in the production of the polyvinyl acetal resin
include formaldehyde (including paraformaldehyde), acetaldehyde
(including paraacetaldehyde), propionaldehyde, butyraldehyde,
n-octylaldehyde, amylaldehyde, hexylaldehyde, heptylaldehyde,
2-ethylhexylaldehyde, cyclohexylaldehyde, furfural, glyoxal,
glutaraldehyde, benzaldehyde, 2-methylbenzaldehyde,
3-methylbenzaldehyde, 4-methylbenzaldehyde, p-hydroxybenzaldehyde,
m-hydroxybenzaldehyde, phenylacetaldehyde, -phenylpropionaldehyde,
and the like. These aldehydes may be used singly or in combination
of two or more.
The polyvinyl acetal resin generally has repeating units
represented by Chemical Formula 1.
##STR00002##
In Chemical Formula 1, n is the number of different types of
aldehyde used in acetalization; R.sub.1, R.sub.2, . . . , R.sub.n,
are independently a (e.g. C1-C7) alkyl residue of aldehyde used in
the acetalization reaction, or a hydrogen atom; k.sub.1, k.sub.2, .
. . , k.sub.n are independently the proportion of each acetal unit
containing R.sub.1, R.sub.2, . . . , R.sub.n, (molar ratio); 1 is
the proportion of vinyl alcohol units (molar ratio); and m is the
proportion of vinyl acetate units (molar ratio). The sum of
k.sub.1+k.sub.2+ . . . +k.sub.n+1+m=1. Further at least one of
k.sub.1, k.sub.2, . . . , k.sub.n may not be zero. When a single
type of aldehyde is utilized in the preparation of the polyvinyl
acetal resin, such single aldehyde may be represented by k.sub.1.
The number of repeat units of k.sub.1+1+m is sufficient to provide
the desired molecular weight. In this embodiment, k.sub.2 and
k.sub.n may be zero. The polyacetal resin is typically a random
copolymer. However, block copolymers and tapered block copolymers
may provide similar benefits as random copolymers.
The content of polyvinyl acetyl (e.g. butyral) typically ranges
from 65 wt-% up to 90 wt-% of the polyvinyl acetal (e.g. butyral)
resin. In some embodiments, the content of polyvinyl acetyl (e.g.
butyral) ranges from about 70 or 75 up to 80 or 85 wt-%. Thus, the
number of repeat units of "k.sub.1, k.sub.2, . . . , k.sub.n" are
selected accordingly.
The content of polyvinyl alcohol typically ranges from about 10 to
30 wt-% of the polyvinyl acetal (e.g. butyral) resin. In some
embodiments, the content of polyvinyl alcohol ranges from about 15
to 25 wt-%. Thus, "1" is selected accordingly.
The content of polyvinyl acetate can be zero or range from 1 to 8
wt-% of the polyvinyl acetal (e.g. butyral) resin. In some
embodiments, the content of polyvinyl acetate ranges from about 1
to 5 wt-%. Thus, "m" is selected accordingly.
In some embodiments, the alkyl residue of aldehyde comprises 1 to 7
carbon atoms. In other embodiments, the alkyl reside of the
aldhehyde comprises 3 to 7 carbon atoms such as in the case of
butylaldehyde (R.sub.1=3), hexylaldehyde (R.sub.1=5),
n-octylaldehyde (R.sub.1=7). Of these butyraldehyde, also known as
butanal is most commonly utilized. Polyvinyl butyral ("PVB") resin
is commercially available from Kuraray under the trade designation
Mowital.TM. and Solutia under the trade designation
"Butvar.TM.".
In some embodiments, the polyvinyl acetal (e.g. butyral) resin has
a Tg ranging from about 60.degree. C. up to about 75.degree. C. or
80.degree. C. In some embodiments, the Tg of the polyvinyl acetal
(e.g. butyral) resin is at least 65 or 70.degree. C. When other
aldehydes, such as n-octyl aldehyde, are used in the preparation of
the polyvinyl acetal resin, the Tg may be less than 65.degree. C.
or 60.degree. C. The Tg of the polyvinyl acetal resin is typically
at least 35, 40 or 45.degree. C. When the polyvinyl acetal resin
has a Tg of less than 60.degree. C., higher concentrations of high
Tg monomers may be employed in the film and (e.g. exemplified)
composition in comparison to those utilizing polyvinyl butyral
resin. When other aldehydes, such as acetaldehyde, are used in the
preparation of the polyvinyl acetal resin, the Tg may be greater
than 75.degree. C. or 80.degree. C. When the polyvinyl acetal resin
has a Tg of greater than 70.degree. C., higher concentrations of
low Tg monomers may be employed in the film and (e.g. exemplified)
composition in comparison to those utilizing polyvinyl acetal
butyral resin.
The polyvinyl acetal (e.g. PVB) resin typically has an average
molecular weight (Mw) of at least 10,000 g/mole or 15,000 g/mole
and no greater than 150,000 g/mole or 100,000 g/mole. In some
favored embodiments, the polyacetal (e.g. PVB) resin has an average
molecular weight (Mw) of at least 20,000 g/mole; 25,000; 30,000,
35,000 g/mole and typically no greater than 75,000 g/mole.
The film and composition comprises 5 to 30 wt-% of polyvinyl acetal
resin such as polyvinyl butyral based on the total weight of the
polymerized units of the (meth)acrylate polymer, polyvinyl acetal
(e.g. butyral) resin, and crosslinker when present. In some
embodiments, the film and composition comprises at least 10, 11,
12, 13, 14, or 15 wt-% of polyvinyl acetal (e.g. PVB) resin. In
some embodiments, the film and composition comprises no greater
than 25 or 20 wt-% of (e.g. prepolymerized) polyvinyl acetal (e.g.
PVB) resin. When the film and composition comprises a polyvinyl
acetal (e.g. PVB) resin having an average molecular weight (Mw)
less than 50,000 g/mole, the film and composition may comprise
higher concentration polyvinyl acetal (e.g. PVB) resin such as 35
or 40 wt-%.
The heat bondable film and composition may comprise a lower amount
of polyvinyl acetal resin such as polyvinyl butyral. In some
embodiments, the heat bondable film and composition comprises at
least 5, 6, 7, 8, 9, or 10 wt-% of polyvinyl acetal resin. In some
embodiments, the heat bonable film and composition comprises no
greater than 20, 19, 18, 17, 16, or 15 wt-% of polyvinyl acetal
resin. When the film and composition comprises a polyacetal (e.g.
PVB) resin having an average molecular weight (Mw) less than 50,000
g/mole, the film and composition may comprise higher concentration
polyvinyl (e.g. PVB) acetal resin such as 25 or 30 wt-%.
In some embodiments, the film and composition comprises a
crosslinker. In some embodiments, the crosslinker is a
multifunctional crosslinker capable of crosslinking polymerized
units of the (meth)acrylic polymer such as in the case of
crosslinkers comprising functional groups selected from
(meth)acrylate, vinyl, and alkenyl (e.g. C3-C20 olefin groups); as
well as chlorinated triazine crosslinking compounds.
Examples of useful (e.g. aliphatic) multifunctional (meth)acrylate
include, but are not limited to, di(meth)acrylates,
tri(meth)acrylates, and tetra(meth)acrylates, such as
1,6-hexanediol di(meth)acrylate, poly(ethylene glycol)
di(meth)acrylates, polybutadiene di(meth)acrylate, polyurethane
di(meth)acrylates, and propoxylated glycerin tri(meth)acrylate, and
mixtures thereof.
In one embodiment, the crosslinking monomer comprises a
(meth)acrylate group and an olefin group. The olefin group
comprises at least one hydrocarbon unsaturation The crosslinking
monomer may have the formula
##STR00003## R1 is H or CH.sub.3, L is an optional linking group;
and R.sub.2 is an olefin group, the olefin group being optionally
substituted.
Dihydrocyclopentadienyl acrylate is one example of this class of
crosslinking monomer. Other crosslinking monomers of this type
comprising a C.sub.6-C.sub.20 olefin are described in
WO2014/172185.
In other embodiments, the crosslinking monomer comprises at least
two terminal groups selected from allyl, methallyl, or combinations
thereof. An allyl group has the structural formula
H.sub.2C.dbd.CH--CH.sub.2--. It consists of a methylene bridge
(--CH.sub.2--) attached to a vinyl group (--CH.dbd.CH.sub.2).
Similarly, a methallyl group is a substituent with the structural
formula H.sub.2C.dbd.C(CH.sub.3)--CH.sub.2--. The terminology
(meth)allyl includes both allyl and methallyl groups. Crosslinking
monomers of this types are described in PCT Publication No.
WO2015/157350.
In some embodiments, the film and composition may comprise a
multifunctional crosslinker comprising vinyl groups, such as in the
case of 1,3-divinyl tetramethyl disiloxane.
The triazine crosslinking compound may have the formula.
##STR00004## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 of this
triazine crosslinking agent are independently hydrogen or alkoxy
group, and 1 to 3 of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are
hydrogen. The alkoxy groups typically have no greater than 12
carbon atoms. In favored embodiments, the alkoxy groups are
independently methoxy or ethoxy. One representative species is
2,4,-bis(trichloromethyl)-6-(3,4-bis(methoxy)phenyl)-triazine. Such
triazine crosslinking compounds are further described in U.S. Pat.
No. 4,330,590.
In other embodiments, the crosslinker comprises hydroxyl-reactive
groups, such as isocyanate groups, capable of crosslinking alkoxy
group of the (meth)acrylic polymer (e.g. HEA) or polyvinyl alcohol
groups of the polyvinyl acetal (PVB). Examples of useful (e.g.
aliphatic) multifunctional isocyanate crosslinkers include
hexamethylene diisocyanate, isophorone diisocyanate, as well as
derivatives and prepolymers thereof.
Various combinations of two or more of crosslinkers may be
employed.
When present, the crosslinker is typically present in an amount of
at least 0.5, 1.0, 1.5, or 2 wt-% ranging up to 5 or 10 wt-% based
on the total weight of the polymerized units of the (meth)acrylate
polymer, polyvinyl acetal (e.g. butyral) resin, and crosslinker.
The heat bondable film and composition may comprise even lower
concentrations of crosslinker, typically ranging from at least
0.05, 0.1, 0.2 0.3, 0.4 or 0.5 wt-% ranging up to 2, 3, 4, or 5
wt-%. Thus the film and composition comprise such amount of
polymerized crosslinker units.
The composition can be polymerized by various techniques, yet is
preferably polymerized by solventless radiation polymerization,
including processes using electron beam, gamma, and especially
ultraviolet light radiation. In this (e.g. ultraviolet light
radiation embodiment, generally little or no methacrylate monomers
are utilized. Thus, the film and composition comprises zero or no
greater than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 wt-% of polymerized
units of monomer having a methacrylate group.
One method of preparing the film and composition described herein
comprises dissolving the polyvinyl acetal (e.g. PVB) polymer in the
unpolymerized solvent monomer(s) of the (meth)acrylic polymer
forming a coatable composition of sufficient viscosity.
Another method includes partially polymerizing the solvent
monomer(s) to produce a syrup composition comprising the solute
(meth)acrylic polymer and unpolymerized solvent monomer(s). The
unpolymerized solvent monomer(s) typically comprises the same
monomer as utilized to produce the solute (meth)acrylic polymer. If
some of the monomers were consumed during the polymerization of the
(meth)acrylic polymer, the unpolymerized solvent monomer(s)
comprises at least some of the same monomer(s) as utilized to
produce the solute (meth)acrylic polymer. Further, the same
monomer(s) or other monomer(s) can be added to the syrup once the
(meth)acrylic polymer has been formed. Partial polymerization
provides a coatable solution of the (meth)acrylic solute polymer in
one or more free-radically polymerizable solvent monomers.
A preferred method of preparation of the syrup composition is
photoinitiated free radical polymerization.
The polyvinyl acetal (e.g. PVB) polymer can be added prior to
and/or after partial polymerization of monomer(s) of the
(meth)acrylic polymer. In this embodiment, the coating composition
comprises partially polymerized (e.g. alkyl(meth)acrylate) solvent
monomers and polyvinyl acetal (e.g. PVB) polymer resin. The
coatable composition is then coated on a suitable substrate and
further polymerized.
The viscosity of the coatable composition is typically at least
1,000 or 2,000 cps ranging up to 100,000 cps at 25.degree. C. In
some embodiments, the viscosity is no greater than 75,000; 50,000,
or 25,000 cps. The coatable composition is coated on a suitable
substrate. such as a release liner, and polymerized by exposure to
radiation.
The method can form a higher molecular weight (meth)acrylic polymer
than can be used by solvent blending a prepolymerized (meth)acrylic
polymer and polyvinyl acetal (e.g. PVB) polymer. Higher molecular
weight (meth)acrylic polymer can increase the amount of chain
entanglements, thus increasing cohesive strength. Also, the
distance between crosslinks can be greater with a high molecular
(meth)acrylic polymer, which allows for increased wet-out onto a
surface of an adjacent (e.g. film) layer.
The molecular weight of the composition can be increased even
further by the inclusion of crosslinker.
In some embodiments, the high molecular weight (meth)acrylic
polymer as well as the composition and film typically has a gel
content (as measured according to the Gel Content Test Method
described in the examples utilizing tetrahydrofuran (THF) of at
least 20, 25 30, 35, or 40%. In some embodiments, the gel content
is at least 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95%. The gel
content is typically less than 100%, 99%, or 98%.
The polymerization is preferably conducted in the absence of
unpolymerizable organic solvents such as ethyl acetate, toluene and
tetrahydrofuran, which are non-reactive with the functional groups
of the solvent monomer and polyvinyl (e.g. PVB) acetal. Solvents
influence the rate of incorporation of different monomers in the
polymer chain and generally lead to lower molecular weights as the
polymers gel or precipitate from solution. Thus, the film and
compositions can be free of unpolymerizable organic solvent.
Useful photoinitiators include benzoin ethers such as benzoin
methyl ether and benzoin isopropyl ether; substituted acetophenones
such as 2,2-dimethoxy-2-phenylacetophenone photoinitiator,
available the trade name IRGACURE 651 or ESACURE KB-1
photoinitiator (Sartomer Co., West Chester, Pa.), and
dimethylhydroxyacetophenone; substituted .alpha.-ketols such as
2-methyl-2-hydroxy propiophenone; aromatic sulfonyl chlorides such
as 2-naphthalene-sulfonyl chloride; and photoactive oximes such as
1-phenyl-1,2-propanedione-2-(O-ethoxy-carbonyl)oxime. Particularly
preferred among these are the substituted acetophenones.
Preferred photoinitiators are photoactive compounds that undergo a
Norrish I cleavage to generate free radicals that can initiate by
addition to the acrylic double bonds. The photoinitiator can be
added to the mixture to be coated after the polymer has been
formed, i.e., photoinitiator can be added to the composition. Such
polymerizable photoinitiators are described, for example, in U.S.
Pat. Nos. 5,902,836 and 5,506,279 (Gaddam et al.).
Such photoinitiators are typically present in an amount of from 0.1
to 1.0 wt-%. Relatively thick coatings can be achieved when the
extinction coefficient of the photoinitiator is low.
The composition and the photoinitiator may be irradiated with
activating UV radiation to polymerize the monomer component(s). UV
light sources can be of various typesincluding relatively low light
intensity sources such as blacklights, which provide generally 10
mW/cm.sup.2 or less (as measured in accordance with procedures
approved by the United States National Institute of Standards and
Technology as, for example, with a UVIMAP UM 365 L-S radiometer
manufactured by Electronic Instrumentation & Technology, Inc.,
in Sterling, Va.) over a wavelength range of 280 to 400 nanometers;
and relatively high light intensity sources such as medium pressure
mercury lamps which provide intensities generally greater than 10
mW/cm.sup.2, preferably 15 to 450 mW/cm.sup.2. Intensities can
range from 0.1 to 150 mW/cm.sup.2, preferably from 0.5 to 100
mW/cm.sup.2, and more preferably from 0.5 to 50 mW/cm.sup.2. The
monomer component(s) can also be polymerized with high intensity
light sources as available from Fusion UV Systems Inc. UV light to
polymerize the monomer component(s) can be provided by light
emitting diodes, blacklights, medium pressure mercury lamps, etc.
or a combination thereof.
The composition and film may optionally contain one or more
conventional additives. Additives include, for example,
antioxidants, stabilizers, ultraviolet absorbers, lubricants,
processing aids, antistatic agents, colorants, impact resistance
aids, fillers, matting agents, flame retardents (e.g. zinc borate)
and the like. In some embodiments, the amount of additive can be at
least 0.1, 0.2, 0.3, 0.4, or 0.5 wt-% and it typically no greater
than 25, 20, 15, 10 or 5 wt-% of the total composition and
film.
In some embodiments, the compositions are free of plasticizer,
tackifier and combinations thereof. In other embodiments, the film
and composition comprise plasticizer, tackifier and combinations
thereof in amount no greater than 5, 4, 3, 2, or 1 wt-% of the
total composition. From the standpoint of tensile strength, it is
preferable not to add a large amount of tackifier or
plasticizer.
In some embodiments, the composition comprises fumed silica. Fumed
silica, also known as pyrogenic silica, is made from flame
pyrolysis of silicon tetrachloride or from quartz sand vaporized in
a 3000.degree. C. electric arc. Fumed silica consists of
microscopic droplets of amorphous silica fused into (e.g. branched)
three-dimensional primary particles that aggregate into larger
particles. Since the aggregates do not typically break down, the
average particle size of fumed silica is the average particle size
of the aggregates. Fumed silica is commercially available from
various global producers including Evonik, under the trade
designation "Aerosil"; Cabot under the trade designation
"Cab-O-Sil", and Wacker Chemie-Dow Corning. The BET surface area of
suitable fumed silica is typically at least 50 m.sup.2/g, or 75
m.sup.2/g, or 100 m.sup.2/g. In some embodiments, the BET surface
area of the fumed silica is no greater than 400 m.sup.2/g, or 350
m.sup.2/g, or 300 m.sup.2/g, or 275 m.sup.2/g, or 250 m.sup.2/g.
The fumed silica aggregates preferably comprise silica having a
primary particle size no greater than 20 nm or 15 nm. The aggregate
particle size is substantially larger than the primary particle
size and is typically at least 100 nm or greater.
The concentration of (e.g. fumed) silica can vary. In some
embodiments, the composition comprises at least 0.5 or 1.0 wt-% of
(e.g. fumed) silica.
In some embodiments, the film and composition comprise colorants
such as pigments and dyes such as titania and carbon black. The
concentration of such pigments and dyes can range up to about 20
wt-% of the total composition.
The inclusion of inorganic oxides such as (e.g. fumed) silica and
titania can increase the tensile strength of the film and
composition.
The compositions can be coated on a (e.g. polyester or
polycarbonate) backing or release liner using conventional coating
techniques. For example, these compositions can be applied by
methods such as roller coating, flow coating, dip coating, spin
coating, spray coating knife coating, and die coating. Coating
thicknesses may vary. The composition may be of any desirable
concentration for subsequent coating, but is typically 5 to 2030,
35 or 40 wt-% polyvinyl acetal polymer solids in (meth)acrylic
solvent monomer. The desired concentration may be achieved by
further dilution of the coating composition, or by partial drying.
The coating thickness may vary depending on the desired thickness
of the (e.g. radiation) cured film.
When the film is a monolithic film, the thickness of the (e.g.
radiation) cured film is typically at least 10, 15, 20, or 25
microns (1 mil) to 500 microns (20 mils) thickness. In some
embodiments, the thickness of the (e.g. radiation) cured film is no
greater than 400, 300, 200, or 100 microns. When the film is a film
layer of a multilayer film, the multilayer film typically has the
thickness just described. However, the thickness of the film layer
comprising the (meth)acrylic polymer and polyvinyl acetal, as
described herein, may be less than 10 microns.
In some embodiments, the thickness of the film may range up to 50,
100, or 150 mils. The (e.g. radiation) cured film may be in the
form of individual sheets, particularly for a thickness of greater
than 20 mils. The (e.g. thinner) cured film may be in the form of a
roll-good.
The composition of the present invention may be coated upon a
variety of flexible and inflexible backing materials using
conventional coating techniques to produce heat bondable films
disposable on a backing, or in otherwords a single coated or double
coated heat bondable tape. Suitable backing materials include but
are not limited to polymeric films, woven or nonwoven fabrics;
metal foils, foams, and combinations thereof (e.g. metalized
polymeric film). Polymeric films include for example polyolefins
such as polypropylene (e.g. biaxially oriented), polyethylene (e.g.
high density or low density), polyvinyl chloride, polyester
(polyethylene terephthalate), polycarbonate,
polymethyl(meth)acrylate (PMMA), polyvinylbutyral, polyimide,
polyamide, fluoropolymer, cellulose acetate, cellulose triacetate,
and ethyl cellulose. In one embodiment, the backing material is a
film comprising a (meth)acrylic monomer and a polyvinyl acetal
(e.g. PVB) resin wherein the film has a Tg of at least 30.degree.
C. typically ranging to 60.degree. C., as described in U.S.
Application No. 62/088,945, filed Dec. 8, 2014, and 75577WO003 PCT
Application filed on even date herewith; incorporated herein by
reference.
The woven or nonwoven fabric may comprise fibers or filaments of
synthetic or natural materials such as cellulose (e.g. tissue),
cotton, nylon, rayon, glass, ceramic materials, and the like. In
some embodiments, the substrate may be comprised of a bio-based
material such as polylactic acid (PLA).
For those heat bondable tapes having sufficient adhesion (e.g. room
temperature 180.degree. peel values without heat bonding) such that
contaminants may accumulate on the surface of the tape and to
protect the surface of the tape prior to use the tape may further
comprise a release material or release liner in the same manner as
single-sided and double-sided pressure sensitive adhesive tapes.
For example, in the case of a single-sided tape, the side of the
backing surface opposite that where the adhesive is disposed is
typically coated with a suitable release material. Release
materials are known and include materials such as, for example,
silicone, polyethylene, polycarbamate, polyacrylics, and the like.
For double coated tapes, another layer of adhesive is disposed on
the backing surface opposite that where the adhesive of the
invention is disposed.
The substrate that is bonded by the heat bondable film may comprise
the same materials as those of the backing.
The film and (e.g. radiation) cured composition can be
characterized using various techniques. Although the Tg of a
copolymer may be estimated by use of the Fox equation, based on the
Tgs of the constituent monomers and the weight percent thereof, the
Fox equation does not take into effect interactions, such as
incompatibility, that can cause the Tg to deviate from the
calculated Tg. The Tg of the film and composition described refers
to the midpoint Tg as measured by Differential Scanning
calorimetry, (DSC), according to the test method described in the
examples. The Tg of the film and (e.g. radiation) cured composition
is less than 30.degree. C., and in some embodiments less than 25 or
20.degree. C. In some embodiments, the film and (e.g. radiation)
cured composition preferably exhibits a single Tg as measured by
DSC. In some embodiments, the Tg of the film and (e.g. radiation)
cured composition is at least 0, 5, 10, 15, 20 or 25.degree. C. In
other embodiments, the Tg of the heat bondable film and (e.g.
radiation) cured composition is typically less than 0, -5 or
-10.degree. C. and typically at least -50.degree. C. or -40.degree.
C. as measured by DSC. The midpoint Tg as measured by DSC of the
film and (e.g. radiation) cured compositions described herein is
10-12.degree. C. lower than the peak temperature Tg as measured by
Dynamic Mechanical Analysis (DMA) at a frequency of 10 Hz and a
rate of 3.degree. C./min.
In some embodiments, the film and (e.g. radiation) cured
composition can be characterized by tensile and elongation
according to the test method described in the examples. In favored
embodiments, the tensile strength is at least 10, 11, 12, 13, 14 or
15 MPa and typically no greater than 50, 45, 40, or 35 MPa. The
elongation at break can range from 2, 3, 4 or 5% up to about 150%,
200%, or 300% and greater. In some favored embodiments, the
elongation is at least 50, 100, or 150%. In some embodiments, the
film is suitable for use as a replacement for polyvinyl chloride
film.
In some embodiments, the film and (e.g. radiation) cured
compositions are preferably non-tacky to the touch at room
temperature (25.degree. C.) and preferably at (e.g. storage or
shipping) temperatures ranging up to (120.degree. F.) 50.degree.
C.
In some embodiments, the films may exhibit a low level of adhesion
to glass or stainless steel. For example, the 180.degree. peel
values can be about 0.5, 1 or 2 N/dm or less at a 12 inch/minute
peel rate. In other embodiments, the 180.degree. peel values of the
heat bondable films and composition can be higher, for example at
least 3, 4, 5, 6, 7, 8, 9, or 10 N/dm and typically no greater than
about 20 N/dm.
In some embodiments, the film and composition is suitable for use
as a heat bondable film or heat bondable film layer disposed on a
substrate. Heat bondable films can generally form a bond at a
temperature ranging from about 50, 60 or 70.degree. C. ranging up
to about 140, 145, or 150.degree. C. In some embodiments, the heat
bonding is accomplished utilizing a pressure of about 5 to 20 psi
for a duration of time of about 5, 10, 15, 20, 25, or 30
seconds.
The heat bondable film is suitable for bonding various metal (e.g.
stainless steel) and polymeric (e.g. polycarbonate) substrates
(such as in the manner described in the test method of the
examples). In one embodiment, the film is heat bondable to
stainless steel at a temperature of 149.degree. C. and exhibits a
peel strength of at least 15 or 20 N/dm ranging up to 50, 75, 100,
125, or 150 N/dm at 25.degree. C. after heat bonding. In another
embodiment, the film is heat bondable to polycarbonate at a
temperature of 120.degree. C. and exhibits a peel strength of at
least 0.5, 0.6, 0.7, or 0.8 kg/cm ranging up to 2, 2.5, or 3 kg/cm
at 25.degree. C. after heat bonding. In another embodiment, the
film is heat bondable to polycarbonate at a temperature of
120.degree. C. and exhibits a peel strength of at least 1, 1.5, or
2 kg/cm ranging up to 3, 3.5, 4.0, 4.5 or 5 kg/cm at 70.degree. C.
after heat bonding.
Herein, "(meth)acryloyl" is inclusive of (meth)acrylate and
(meth)acrylamide.
Herein, "(meth)acrylic" includes both methacrylic and acrylic.
Herein, "(meth)acrylate" includes both methacrylate and
acrylate.
The term "alkyl" includes straight-chained, branched, and cyclic
alkyl groups and includes both unsubstituted and substituted alkyl
groups. Unless otherwise indicated, the alkyl groups typically
contain from 1 to 20 carbon atoms. Examples of "alkyl" as used
herein include, but are not limited to, methyl, ethyl, n-propyl,
n-butyl, n-pentyl, isobutyl, t-butyl, isopropyl, n-octyl, 2-octyl,
n-heptyl, ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl,
adamantyl, and norbornyl, and the like. Unless otherwise noted,
alkyl groups may be mono- or polyvalent.
The term heteroalkyl refers to an alkyl group, as just defined,
having at least one catenary carbon atom (i.e. in-chain) replaced
by a catenary heteroatom such as O, S, or N.
"Renewable resource" refers to a natural resource that can be
replenished within a 100 year time frame. The resource may be
replenished naturally or via agricultural techniques. The renewable
resource is typically a plant (i.e. any of various photosynthetic
organisms that includes all land plants, inclusive of trees),
organisms of Protista such as seaweed and algae, animals, and fish.
They may be naturally occurring, hybrids, or genetically engineered
organisms. Natural resources such as crude oil, coal, and peat
which take longer than 100 years to form are not considered to be
renewable resources.
When a group is present more than once in a formula described
herein, each group is "independently" selected unless specified
otherwise.
The invention includes but is not limited to the following
embodiments.
Embodiment 1 is a film comprising:
(meth)acrylic polymer and polyvinyl acetal resin comprising
polymerized units having the following formula
##STR00005## wherein R.sub.1 is hydrogen or a C1-C7 alkyl group;
wherein the film has a tensile elastic modulus of at least 1 MPa at
25 C and 1 hertz and a Tg less than 30.degree. C.
Embodiment 2 is the film Embodiment 1 wherein the film comprises at
least 25, 30, 35, 40, 50 wt-% of polymerized units of
monofunctional alkyl (meth)acrylate monomer having a Tg of less
than 0.degree. C.
Embodiment 3 is the film of Embodiment 2 wherein the film comprises
no greater than 85 wt-% of polymerized units of monofunctional
alkyl (meth)acrylate monomer having a Tg of less than 0.degree.
C.
Embodiment 4 is the film of Embodiments 2 or 3 wherein the
monofunctional alkyl (meth)acrylate monomer has a Tg of less than
-10.degree. C., -20.degree. C., -30.degree. C., -40.degree. C., or
-50.degree. C.
Embodiment 5 is the film of Embodiments 1-4 wherein the film
comprises a bio-based content of at least 25 or 50% of the total
carbon content.
Embodiment 6 is the film of Embodiments 1-5 wherein the film
comprises polymerized units of an alkyl (meth)acrylate monomer
having an alkyl group with 8 carbon atoms.
Embodiment 7 is the film of Embodiments 1-6 wherein the film
further comprises up to 20 wt-% of polymerized units of a
monofunctional alkyl (meth)acrylate monomer having a Tg greater
than 40.degree. C., 50.degree. C., 60.degree. C., 70.degree. C., or
80.degree. C.
Embodiment 8 is the film of Embodiments 1-7 wherein the film
further comprises at least 5, 10, 15 or 20 wt-% and no greater than
65 wt-% of polymerized units of polar monomers.
Embodiment 9 is the film of Embodiment 8 wherein polar monomers are
selected from acid-functional, hydroxyl functional monomers,
nitrogen-containing monomers, and combinations thereof.
Embodiment 10 is the film of Embodiments 1-9 wherein the film
comprises polyvinyl butyral.
Embodiment 11 is the film of Embodiments 1-10 wherein the film
comprises 5 to 20 wt-% of polyvinyl acetal resin.
Embodiment 12 is the film of Embodiments 1-11 wherein the polyvinyl
acetal resin has a polyvinyl alcohol content ranging from 10 to 30
wt-%.
Embodiment 13 is the film of Embodiments 1-12 wherein the polyvinyl
acetal resin has a glass transition temperature ranging from
60.degree. C. to 75.degree. C.
Embodiment 14 is the film of Embodiments 1-13 wherein the
polyacetal resin has an average molecular weight (Mw) ranging from
10,000 g/mole to 100,000 g/mole.
Embodiment 15 is the film of Embodiments 1-14 wherein the film
further comprises polymerized units of a multifunctional
crosslinker wherein the crosslinker is a traizine crosslinker or
comprises functional groups selected from (meth)acrylate, alkenyl,
and hydroxyl-reactive groups.
Embodiment 16 is the film of Embodiments 1-15 wherein the film
further comprises additives in an amount no greater than 25
wt-%.
Embodiment 17 is the film Embodiments 1-16 wherein the film
comprises photoinitiator.
Embodiment 18 is the film composition of Embodiments 1-17 wherein
the film comprises no greater than 10 wt-% of polymerized units of
methacrylate monomers.
Embodiment 19 is the film composition of Embodiments 1-18 wherein
the (meth)acrylic polymer is a random copolymer.
Embodiment 20 is the film of Embodiments 1-19 wherein the film is a
monolithic film.
Embodiment 21 is the film of Embodiments 1-19 wherein the film is a
film layer of a multilayer film.
Embodiment 22 is a method of making a film comprising:
a) providing a composition comprising
i) polyvinyl acetal resin comprising polymerized units having the
following formula
##STR00006##
wherein R.sub.1 is hydrogen or a C1-C7 alkyl group; and
ii) free-radically polymerizable solvent monomer;
b) applying the composition to a substrate; and
c) polymerizing and optionally crosslinking the composition thereby
forming a film having a tensile elastic modulus of at least 1 MPa
at 25 C and 1 hertz and a Tg less than 30.degree. C.
Embodiment 23 is the method of Embodiment 22 wherein the substrate
is a release liner.
Embodiment 24 is the method of Embodiments 22-23 wherein the
crosslinking comprises free-radical polymerization.
Embodiment 25 is the method of Embodiment 24 wherein the
crosslinking comprise curing by exposure to ultraviolet
radiation.
Embodiment 26 is the method of Embodiments 22-25 further
characterized by any one or combination of Embodiments 2-21.
Embodiment 27 is a composition comprising (meth)acrylic polymer and
polyvinyl acetal resin comprising polymerized units having the
following formula
##STR00007##
wherein R.sub.1 is hydrogen or a C1-C7 alkyl group;
wherein the composition has a tensile elastic modulus of at least 1
MPa at 25 C and 1 hertz and a Tg less than 30.degree. C.
Embodiment 28 is the composition of Embodiment 27 further
characterized by any one or combination of Embodiments 2-19.
Embodiment 29 is the multilayer film of Embodiment 21 disposed on
at least one major surface of a backing.
Embodiment 30 is the multilayer film of Embodiment 21 comprising
the film of claims 1-19 disposed on both major surfaces of a
backing.
Embodiment 31 is the film of Embodiments 1-21, 29, 30 wherein the
film comprises at least 55, 60, 65, 70, or 76 wt-% of polymerized
units of monofunctional alkyl (meth)acrylate monomer having a Tg of
less than 0.degree. C.
Embodiment 32 is the film of Embodiments 1-19 and 29-31 wherein the
film is heat bondable to stainless steel at a temperature of
149.degree. C. and exhibits a peel strength of at least 20 N/dm at
25.degree. C. after heat bonding.
Embodiment 33 is the film of Embodiments 1-19 and 29-31 wherein the
film is heat bondable to polycarbonate at a temperature of
100.degree. C. and exhibits a peel strength of at least 1
pound/inch at 25.degree. C. after heat bonding.
Embodiment 34 is a method of bonding comprising providing a film
according to any of the previous embodiments; contacting the film
with a least one substrate; and bonding the substrate by means of
heat and pressure with the film.
Objects and advantages of this invention are further illustrated by
the following examples. The particular materials and amounts, as
well as other conditions and details, recited in these examples
should not be used to unduly limit this invention.
EXAMPLES
TABLE-US-00002 TABLE 1 Glossary of Materials Designation
Description Source B60HH Polyvinyl butyral, ~60,000 g/mol, Kurarary
America, Inc. available under the trade designation (Houston, TX,
USA) "MOWITAL B 60 HH" B30HH Polyvinyl butyral, ~30,000 g/mol,
Kurarary America, Inc. available under the trade designation
(Houston, TX, USA) "MOWITAL B 30 HH" B60H Polyvinyl butyral,
~60,000 g/mol, Kurarary America, Inc. available under the trade
designation (Houston, TX, USA) "MOWITAL B 60 H" CAP Cellulose
acetate propionate, available Eastman Chemical under the trade
designation "CAP-482- Company (Kingsport, TN, 20" USA) PVAc
Polyvinyl acetate, ~40,000 g/mol Alfa Aesar (Ward Hill, MA, USA)
PVP Polyvinyl pyrrolidone, ~50,000 g/mol Alfa Aesar (Ward Hill, MA,
USA) PCL Polycaprolactone resin, ~50,000 g/mol, Perstorp Holding AB
available under the trade designation (Perstorp, Sweden) "CAPA
6500" Low Tg Monomer Iso-octyl acrylate 3M Company (St. Paul, IOA
(Tg = -70.degree. C.) MN, USA) Low Tg Monomer 2-Octyl acrylate
Prepared according to 2OA (Tg = -45.degree. C.) Preparatory Example
1 of U.S. Pat. No. 7,385,020 Low Tg Monomer 2-Ethylhexyl acrylate
BASF Corporation EHA (Tg = -50.degree. C.) (Florham Park, NJ, USA)
Polar Monomer 2-Hydroxyethyl acrylate Kowa American HEA Corporation
(New York, (Tg = 4.degree. C.) NY, USA) Polar Monomer
4-Hydroxybutyl acrylate BASF Corporation HBA (Florham Park, NJ,
USA) (Tg = -40.degree. C.) High Tg Monomer Isobornyl acrylate San
Ester Corporation IBOA (New York, NY, USA) (Tg = 94.degree. C.)
High Tg Polar Monomer Acrylic acid BASF Corporation AA (Tg =
106.degree. C.) (Florham Park, NJ, USA) High Tg Polar
N-vinylpyrrolidone TCI America, Monomer Montgomeryville, PA NVP (Tg
= 54.degree. C.) High Tg Polar N,N-dimethylacrylamide Sigma-Aldrich
Monomer Company (St. Louis, NNDMA (Tg = 89.degree. C.) MO, USA) CD
9055 acid acrylate available under the Sartomer, Exton, PA, (Tg =
<30.degree. C.) trade designation "CD 9055" IRGACURE 651 An
initiator avalailable under the trade BASF Corporation designation
"IRGACURE 651" (Florham Park, NJ, USA) CN965 Crosslinker A urethane
acrylate available under the Sartomer America (Exton, trade
designation "CN965 Urethane PA, USA) Acrylate" DPA Crosslinker
Dihydrocyclopenadienyl acrylate BASF Corporation (Florham Park, NJ,
USA) HDDA Crosslinker 1,6-hexanediol diacrylate Cytec Industries,
Inc. (Woodland Park, NJ, USA) T1 Crosslinker
2,4-bis-Trichloromethyl-6-(4-methoxy- Can be prepared according
phenyl)-1,3,5-triazine to Wakabayashi et al., Bull. Chem. Soc. Jap,
Vol. 42, pages 2924-2930 (1969) D12A Crosslinker Linear aromatic
urethane blocked Bayer Material Science, isocyanate with ether
groups, available LLC (Pittsburgh, PA, under the trade designation
USA) "DESMOCAP 12A" D11A Crosslinker Branched aromatic urethane
blocked Bayer Material Science, isocyante with ether groups,
available LLC (Pittsburgh, PA, under the trade designation USA)
"DESMOCAP 11A" TMPDE Crosslinker Trimethylolpropane diallyl ether,
Perstorp Holding AB available under the trade designation
(Perstorp, Sweden) "TMPDE 90" DVTD Crosslinker 1,3-Divinyl
tetramethyl disiloxane), Gelest, Inc. (Morristown, available under
the trade designation PA, USA) "SID4613.0" CN963B80 Crosslinker An
aliphatic polyester based urethane Sartomer, Exton, PA diacrylate
oligomer blended with 20% SR238, hexane diol diacrylate available
under the trade designation "CN 963 B80" DESMODUR .TM. Aliphatic
polyisocyanate available Bayer Material Science, N3800 under the
trade designation Pittsburgh, PA "DESMODUR N3800" TiO.sub.2 Pigment
Titanium dioxide Kronus, Inc., Dallas, TX T10 T10 release liner
Solutia, Inc. (St Louis, MO, USA) HOSTAPHAN 3SAB Polyetheylene
terepthalate (PET) film, Mitsubishi Polyester Film, available under
the trade designation Inc. (Greer, SC, USA) "HOSTAPHAN 3SAB" 467MP
ADHESIVE A transfer tape available under the trade 3M Company (St.
Paul, TRANSFER TAPE designation "467MP ADHESIVE MN, USA) TRANSFER
TAPE" Fumed Silica HDK .RTM. H15 Pyrogenic Silica Wacker Chemie AG
(Munich, Germany)
Test Method 1: 70.degree. C. Peel Adhesion to Polycarbonate (PC)
(A) Sample Preparation
The cured (meth)acrylic polyvinyl butyral films were heat laminated
onto a polycarbonate/polybutylene terephthalate (PC/PBT) film
(BAYFOL.RTM. CR 210 000000, Bayer Material Science, 7 mil (178
micrometers) thick) and then cut into 0.5 inch (1.27 cm) by 4 inch
(10.16 cm) strips and heat laminated to 2 inch (5.08 cm) by 4 inch
(10.16 cm) polycarbonate panel (EXL 1132T Resin, available from
Sabic Innovative Plastics, Pittsfield, Mass.). Both lamination
steps used a heat bonder under the trade designation "CERATEK
(Model 12ASL/1)" by Sencorp White Company, Hyannis, Mass., with
temperature setting at 285.degree. F. (140.degree. C.) on the top
platen and 158.degree. F. (70.degree. C.) on the bottom platen for
30 seconds at a pressure of 10 PSI (0.689 MPa). The actual
temperature of the bondline was 120.degree. C. as measured by a
thermocouple.
(B) 70.degree. C. Peel Adhesion Testing
90 Degree peel performance of the heat laminated films of (A) was
measured according to ASTM D6862-11 with a test rate of 12 in/min
(30.48 cm/min). The sample size was 0.5 inch (1.27 cm) width by 4.0
inches (10.16 cm) length on PC substrates at room temperature
("RT") and 70.degree. C. The samples tested at 70.degree. C. were
equilibrated in the oven for at least 15 minutes before peeling.
The average peel strength was reported for each sample in lbf/inch
and converted to kg/cm.
Test Method 2: 180.degree. Peel Adhesion to Stainless Steel after
Heat Treatment
Examples of heat bondable films that were coated and cured on
HOSTAPHAN 3SAB primed PET were tested to determine their peel
adhesions on stainless steel. Each sample, 2 layer film
construction was cut into 2 samples strips, 1 inch (2.54 cm) by 10
inches (25.4 cm) in dimension. Stainless steel panels were washed
once with acetone, three times with n-heptane, and allowed to dry.
Samples were rolled down with a 4.5 lb (2.04 kg) mechanical roller
onto steel panels and placed in a 300.degree. F. (148.9.degree. C.)
oven for 10 minutes. Samples were allowed to cool to room
temperature for 2 hours. Heat bondable 2 layer film constructions
were then peeled from stainless steel panels at 180.degree. peel
angle on an IMASS SP-2100 slip/peel tester from Instrumentors, Inc.
(Strongsville, Ohio) at a rate of 12''/min. Peel adhesion values
were averaged for each example, recorded in oz/in, and converted to
N/dm.
Test Method 3: 180.degree. Peel Adhesion to Stainless Steel without
Heat Treatment
Examples of heat bondable films that were coated and cured on
HOSTAPHAN 3SAB primed PET were tested to determine their peel
adhesions on stainless steel. Each example 2 layer film
construction was cut into 2 samples strips, 1 inch (2.54 cm) by 10
inches (25.4 cm) in dimension. Stainless steel panels were washed
once with acetone, three times with n-heptane, and allowed to dry.
Samples were rolled down with a 4.5 lb (2.04 kg) mechanical roller
onto steel panels and were dwelled at room temperature for 2 hours.
Heat bondable 2 layer film constructions were then peeled from
stainless steel panels at 180.degree. peel angle on an IMASS
SP-2100 slip/peel tester from Instrumentors, Inc. (Strongsville,
Ohio) at a rate of 12''/min. Peel adhesion values were averaged for
each example, recorded in oz/in, and converted to N/dm.
Test Method 4: Determination of Tensile Storage Modulus (E')
The examples were analyzed by Dynamic Mechanical Analysis (DMA)
using a DMAQ800 from TA Instruments in tensile mode to characterize
the physical properties of each sample as a function of
temperature. Rectangular samples, 6.2 mm wide and 0.05-0.07 mm
thick, were clamped into the film tension clamps of the instrument
at 17-19 mm length. The furnace was closed and the temperature was
equilibrated at -50.degree. C. and held for 5 minute. The
temperature was then ramped from -50.degree. C. to 50.degree. C. at
2.degree. C./min while the sample was oscillated at a frequency of
1 Hertz and a constant strain of 0.1 percent. While many physical
parameters of the material were recorded during the temperature
ramp, tensile storage modulus (E') was of primary importance and
its value at 25.degree. C. was recorded in MPa.
Test Method 5: Differential Scanning Calorimetry
DSC was performed on a MODEL Q2000 DSC instrument (TA Instruments
Inc., New Castle, Del., USA). DSC samples were typically 6 to 20
milligrams. Testing was done in sealed, aluminum, T-zero sample
pans. For each sample analysis, pans were individually placed on
one of the differential posts in the DSC's enclosed cell along with
an empty reference pan on the opposite post. Over the course of the
test the temperature was raised to 150.degree. C., lowered to
-85.degree. C., equilibrated for 2 minutes, and then raised to
150.degree. C. All temperature changes were carried out at
20.degree. C./min except for Examples 55 and 56 that were carried
out at 5.degree. C./min. The second heating cycle was used to
determine the Tg, referring to the midpoint temperature, described
as T.sub.mg in ASTM D3418-12.
Test Method 6: Tensile Strength and Elongation Test
Tensile and elongation testing was conducted according to ASTM
D882-10 (unless specified otherwise) utilizing an INSTRON MODEL
4500 UNIVERSAL TESTING SYSTEM with a 1 kN load cell. Testing was
performed at a rate of 300 mm/minute (11.81 inches/minute) for a
total distance of 250 mm (9.84 inches). Samples were tested at
least 24 hours after being prepared. A 0.5'' (.about.1.3 cm) wide
strip of film was cut, and the thickness was determined for each
sample using a micrometer. Typical sample length is 5-7 cm (2-3
inches). Test results were reported as the average of 3-5 sample
replicates. The tensile strength (nominal) and percent elongation
at break were determined, as described by 11.3 and 11.5 of ASTM
D882-10.
Heat Bondable Films (HBF) Made with DPA as a Crosslinker
Example 1
The base formulation was made by combining 270 grams (81.3 wt. %)
of IOA, 30 grams (9.3 wt. %) of AA, 24 grams (7.4 wt. %) of B60HH,
and 1.05 gram (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Film was made by combining 50 grams of base
formulation and a quantity of DPA according to Table 2 in a smaller
jar, rolling overnight, coating onto a release liner at a 2 mil
(50.8 micrometer) thickness, and curing under a nitrogen atmosphere
with 559 mJ/cm.sup.2 of UV A light over 2 minutes. Thus, the
thickness of the resulting cured film was 2 mils (50.8
micrometer).
Examples 2-4
The base formulation was made by combining 540 grams (81.8 wt. %)
of IOA, 60 grams (9.1 wt. %) of AA, 60 grams (9.1 wt. %) of B60HH,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous.
Example 2 was made by combining 50 grams of base formulation and a
quantity of DPA according to Table 2 in a smaller jar, rolling
overnight, and coating and curing as described above.
Example 3 was made in the same fashion as Example 2 except that 0.5
gram (1.0 phr) of D11A was added in addition to the DPA ahead of
rolling overnight.
Example 4 was made in the same fashion as Example 2 except that 0.5
gram (1.0 phr) of D12A was added in addition to the DPA ahead of
rolling overnight.
Example 5
The base formulation was made by combining 277.5 grams (84.1 wt. %)
of IOA, 22.5 grams (6.8 wt. %) of AA, 30 grams (9.1 wt. %) of
B60HH, and 1.05 gram (0.32 phr) of IRGACURE 651 in a glass quart
jar and mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Film was made by combining 50 grams of base
formulation and a quantity of DPA according to Table 2 in a smaller
jar, rolling overnight, and coating and curing as described
above.
Example 6
The base formulation was made by combining 270 grams (81.8 wt. %)
of IOA, 30 grams (9.1 wt. %) of AA, 30 grams (9.1 wt. %) of B60HH,
and 1.05 gram (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Film was made by combining 50 grams of base
formulation and a quantity of DPA according to Table 2 in a smaller
jar, rolling overnight, and coating and curing as described
above.
Example 7
The base formulation was made by combining 270 grams (80.6 wt. %)
of IOA, 30 grams (9.0 wt. %) of AA, 35 grams (10.4 wt. %) of B60HH,
and 1.05 gram (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Film was made by combining 50 grams of base
formulation and a quantity of DPA according to Table 2 in a smaller
jar, rolling overnight, and coating and curing as described
above.
Examples 8-12
The base formulation was made by combining 540 grams (79.6 wt. %)
of IOA, 60 grams (8.8 wt. %) of AA, 78 grams (11.5 wt. %) of B60HH,
and 2.1 grams (0.31 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous.
Examples 8-10 were made by combining 50 grams of base formulation
and a quantity of DPA according to Table 2 in a smaller jar,
rolling overnight, and coating and curing as described above.
Example 11 was made in the same fashion as Example 8 except that
0.5 gram (1.0 phr) of D11A was added in addition to the DPA ahead
of rolling overnight.
Example 12 was made in the same fashion as Example 8 except that
0.5 gram (1.0 phr) of D12A was added in addition to the DPA ahead
of rolling overnight.
Example 13
The base formulation was made by combining 270 grams (76.9 wt. %)
of IOA, 30 grams (8.5 wt. %) of AA, 51 grams (14.5 wt. %) of B60HH,
and 1.05 gram (0.30 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Film was made by combining 50 grams of base
formulation and a quantity of DPA according to Table 2 in a smaller
jar, rolling overnight, and coating and curing as described
above.
Examples were tested according to Test Method 1. Additionally,
Examples 1, 4, 5, 7, and 13 were tested according to Test Method 4,
and Examples 2, 6, 9, 11, and 13 were tested according to Test
Method 5.
TABLE-US-00003 TABLE 2 Properties of Heat Bondable Films made using
DPA as a crosslinker RT Peel 70.degree. C. Peel Adhesion Adhesion
E' at Example IOA AA B60HH DPA DPA (lbf/in, (lbf/in, 25.degree. C.
Tg # (wt. %) (wt. %) (wt. %) (g) (phr) kg/cm) kg/cm) (MPa)
(.degree. C.) 1 83.3 9.3 7.4 1.0 2 11.0, 1.96 16.1, 2.88 5.25 n.m.
2 81.8 9.1 9.1 0.5 1 9.9, 1.77 16.2, 2.89 n.m. -40.6 3 81.8 9.1 9.1
0.5 1 8.7, 1.55 14.7, 2.63 n.m. -38.3 4 81.8 9.1 9.1 0.5 1 8.9,
1.59 16.6, 2.96 6.18 -37.7 5 84.1 6.8 9.1 1.0 2 4.5, 0.80 16.5,
2.95 48.95 -37.8 6 81.8 9.1 9.1 1.0 2 9.5, 1.70 21.0, 3.75 n.m.
-33.9 7 80.6 9.0 10.4 1.0 2 9.3, 1.66 20.0, 3.57 12.70 n.m. 8 79.6
8.8 11.5 1.0 2 9.7, 1.73 19.2, 3.43 n.m. n.m. 9 79.6 8.8 11.5 1.5 3
7.9, 1.41 17.4, 3.11 n.m. -31.9 10 79.6 8.8 11.5 2.0 4 7.3, 1.30
15.9, 2.84 n.m. n.m. 11 79.6 8.8 11.5 1.0 2 8.3, 1.48 16.9, 3.02
n.m. -32.4 12 79.6 8.8 11.5 1.0 2 8.6, 1.54 22.0, 3.93 n.m. n.m. 13
76.9 8.5 14.5 1.0 2 7.1, 1.27 14.1, 2.52 36.50 -37.8 n.m.--not
measured
Heat Bondable Films (HBF) Made with T1 as a Crosslinker
Example 14
The base formulation was made by combining 270 grams (81.3 wt. %)
of IOA, 30 grams (9.3 wt. %) of AA, 24 grams (7.4 wt. %) of B60HH,
and 1.05 gram (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Film was made by combining 50 grams of base
formulation and a quantity of T1 according to Table 3 in a smaller
jar, rolling overnight, coating onto a release liner at a 2 mil
(50.8 micrometer) thickness, and curing under a nitrogen atmosphere
with 559 mJ/cm.sup.2 of UV A light over 2 minutes.
Examples 15-19
Example 15 was made in the same fashion as Example 14 except the
composition of the base formulation was 277.5 grams (84.1 wt. %) of
IOA, 22.5 grams (6.8 wt. %) of AA, 30 grams (9.1 wt. %) of B60HH,
and 1.05 gram (0.32 phr) of IRGACURE 651.
Example 16 was made in the same fashion as Example 14 except the
composition of the base formulation was 270 grams (81.8 wt. %) of
IOA, 30 grams (9.1 wt. %) of AA, 30 grams (9.1 wt. %) of B60HH, and
1.05 gram (0.32 phr) of IRGACURE 651.
Example 17 was made in the same fashion as Example 14 except the
composition of the base formulation was 277.5 grams (81.9 wt. %) of
IOA, 22.5 grams (6.6 wt. %) of AA, 39 grams (11.5 wt. %) of B60HH,
and 1.05 gram (0.32 phr) of IRGACURE 651.
Example 18 was made in the same fashion as Example 14 except the
composition of the base formulation was 270 grams (79.6 wt. %) of
IOA, 30 grams (8.8 wt. %) of AA, 39 grams (11.5 wt. %) of B60HH,
and 1.05 gram (0.31 phr) of IRGACURE 651.
Example 19 was made in the same fashion as Example 14 except the
composition of the base formulation was 270 grams (76.9 wt. %) of
IOA, 30 grams (8.5 wt. %) of AA, 51 grams (14.5 wt. %) of B60HH,
and 1.05 gram (0.30 phr) of IRGACURE 651.
Examples were tested according to Test Method 1. Additionally,
Example 16 was tested according to Test Method 5.
TABLE-US-00004 TABLE 3 Properties of Heat Bondable Films made using
T1 as a crosslinker RT Peel 70.degree. C. Peel Adhesion Adhesion
Example IOA AA B60HH T1 T1 (lbf/in, (lbf/in, # (wt. %) (wt. %) (wt.
%) (g) (phr) kg/cm) kg/cm) Tg (.degree. C.) 14 83.3 9.3 7.4 0.1 0.2
10.1, 1.80 16.4, 2.93 n.m. 15 84.1 6.8 9.1 0.1 0.2 6.2, 1.11 4.5,
2.59 n.m. 16 81.8 9.1 9.1 0.1 0.2 9.2, 1.64 5.8, 2.82 -38.4 17 81.9
6.6 11.5 0.1 0.2 4.8, 0.86 16.1, 2.88 n.m. 18 79.6 8.8 11.5 0.1 0.2
11.9, 2.13 15.2, 2.71 n.m. 19 76.9 8.5 14.5 0.1 0.2 11.1, 1.98 4.8,
2.64 n.m. n.m. not measured
Heat Bondable Films (HBF) Made with HDDA as a Crosslinker
Example 20
The base formulation was made by combining 277.5 grams (84.1 wt. %)
of IOA, 30 grams (6.8 wt. %) of AA, 30 grams (9.1 wt. %) of B60HH,
and 1.05 gram (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a Netzsch Model 50 Dispersator until clear and
homogeneous. Film was made by combining 50 grams of base
formulation and a quantity of HDDA according to Table 4 in a
smaller jar, rolling overnight, coating onto a release liner at a 2
mil (50.8 micrometer) thickness, and curing under a nitrogen
atmosphere with 559 mJ/cm.sup.2 of UV A light over 2 minutes.
Examples 21-23
Example 21 was made in the same fashion as Example 20 except the
composition of the base formulation was 270 grams (81.8 wt. %) of
IOA, 30 grams (9.1 wt. %) of AA, 30 grams (9.1 wt. %) of B60HH, and
1.05 gram (0.32 phr) of IRGACURE 651.
Example 22 was made in the same fashion as Example 20 except the
composition of the base formulation was 262.5 grams (79.5 wt. %) of
IOA, 37.5 grams (11.4 wt. %) of AA, 30 grams (9.1 wt. %) of B60HH,
and 1.05 gram (0.32 phr) of IRGACURE 651.
Example 23 was made in the same fashion as Example 20 except the
composition of the base formulation was 270 grams (80.6 wt. %) of
IOA, 30 grams (9.0 wt. %) of AA, 35 grams (10.4 wt. %) of B60HH,
and 1.05 gram (0.31 phr) of IRGACURE 651.
Examples were tested according to Test Method 1. Additionally,
Example 23 was tested according to Test Method 5.
TABLE-US-00005 TABLE 4 Properties of HBFs made using HDDA as a
crosslinker RT Peel 70.degree. C. Peel Adhesion Adhesion Example
IOA AA B60HH HDDA HDDA (lbf/in, (lbf/in, # (wt. %) (wt. %) (wt. %)
(g) (phr) kg/cm) kg/cm) Tg (.degree. C.) 20 84.1 6.8 9.1 0.05 0.1
6.8, 1.21 18.4, 3.29 n.m. 21 81.8 9.1 9.1 0.05 0.1 5.4, 0.96 22.6,
4.04 n.m. 22 79.5 11.4 9.1 0.05 0.1 5.6, 1.00 n.m. n.m. 23 80.6 9.0
10.4 0.05 0.1 10.0, 1.79 20.9, 3.73 -37.5 n.m. not measured
Heat Bondable Films Made with B30HH
Examples 24-26
The base formulation was made by combining 540 grams (81.8 wt. %)
of IOA, 60 grams (9.1 wt. %) of AA, 60 grams (9.1 wt. %) of B30HH,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Tapes 24, 25, and 26 were made by combining 100 grams
of base formulation and a quantity of crosslinker according to
Table 5 in a smaller jar, rolling overnight, coating onto a release
liner at 2 mil (50.8 micrometer) thickness, and curing under a
nitrogen atmosphere with 559 mJ/cm.sup.2 of UV A light over 2
minutes.
Examples 27-29
The base formulation was made by combining 540 grams (79.4 wt. %)
of IOA, 60 grams (8.8 wt. %) of AA, 78 grams (11.5 wt. %) of B30HH,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Tapes 27, 28, and 29 were made by combining 100 grams
of base formulation and a quantity of crosslinker according to
Table 5 in a smaller jar, rolling overnight, coating onto a release
liner at 2 mil (50.8 micrometer) thickness, and curing under a
nitrogen atmosphere with 559 mJ/cm.sup.2 of UV A light over 2
minutes.
Examples 24-29 were tested according to Test Methods 1 and 5.
Additionally, Example 27 was tested according to Test Method 4.
TABLE-US-00006 TABLE 5 Properties of HBFs with B30HH RT Peel
70.degree. C. Peel Adhesion Adhesion E' at Example Crosslinker
Crosslinker Crosslinker (lbf/in, (lbf/in, 25.degree. C. # linker
(g) (phr) kg/cm) kg/cm) (MPa) Tg (.degree. C.) 24 DPA 2.0 2.0 12.4,
2.21 19.0, 3.38 n.m. -35.9 25 HDDA 0.1 0.1 10.4, 1.85 20.2, 3.59
n.m. -38.2 26 T1 0.1 0.1 11.4, 2.03 21.5, 3.83 n.m. -38.0 27 DPA
2.0 2.0 9.6, 1.71 20.2, 3.59 9.84 -35.4 28 HDDA 0.1 0.1 10.7, 1.90
19.3, 3.43 n.m. -38.3 29 T1 0.1 0.1 14.2, 2.53 19.1, 3.40 n.m.
-39.4 n.m. not measured
Heat Bondable Films with Backing (2 Layer Film Constructions)
Examples 30-34
The base formulation was made by combining 540 grams (81.8 wt. %)
of IOA, 60 grams (9.1 wt. %) of AA, 60 grams (9.1 wt. %) of B60HH,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Tapes 30, 32, and 34 were made by combining 100 grams
of base formulation and a quantity of crosslinker according to
Table 6 in a smaller jar, rolling overnight, coating onto HOSTAPHAN
3SAB primed PET at 2 mil (50.8 micrometer) thickness, and curing
under a nitrogen atmosphere with 559 mJ/cm.sup.2 of UV A light over
2 minutes.
Example 31 was made in the same fashion as Example 24 except that
1.0 gram (1.0 phr) of D12A was added in addition to the crosslinker
ahead of rolling overnight.
Example 33 was made in the same fashion as Example 26 except that
1.0 gram (1.0 phr) of D12A was added in addition to the crosslinker
ahead of rolling overnight.
Examples 35-38
The base formulation was made by combining 540 grams (81.8 wt. %)
of 2OA, 60 grams (9.1 wt. %) of AA, 60 grams (9.1 wt. %) of B60HH,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Tapes 35-38 were made by combining 100 grams of base
formulation and a quantity of crosslinker according to Table 6 in a
smaller jar, rolling overnight, coating onto HOSTAPHAN 3SAB primed
PET at a 2 mil (50.8 micrometer) thickness, and curing under a
nitrogen atmosphere with 559 mJ/cm.sup.2 of UV A light over 2
minutes.
Example 39
The film formulation was made by combining 856 grams (24.0 wt. %)
of EHA, 640 grams (32.0 wt %) of IBOA, 358 grams (10.0 wt. %) of
HEA, 358 grams (10.0 wt %) of AA, 600 grams (16.8 wt %) of B60H,
250 grams (7.0 wt %) of CN965, 7.13 grams (0.20 wt. %) of IRGACURE
651 in a glass gallon jar and mixed with a NETZSCH MODEL 50
DISPERSATOR until clear and homogeneous. The heat bondable
formulation was made by combining 79.2 grams (79.2 wt. %) of IOA,
8.8 grams (8.8 wt. %) of AA, 8.8 grams (8.8 wt. %) of B60HH, 2.9
grams (2.9 wt %) of DPA and 0.3 gram (0.3 phr) of 651 in a glass
quart jar and mixing with a NETZSCH MODEL 50 DISPERSATOR until
clear and homogeneous. The film formulation was then coated between
a release liners at 2 mil (50.8 micrometer) thickness, and cured
with 1,824 mJ/cm.sup.2 of UV A light over 3.8 minutes. The heat
bondable formulation was then coated directly between the cured
film formulation and a release liner at 2 mil (50.8 micrometer)
thickness, and curing with 1,200 mJ/cm.sup.2 of UV A light over 5
minutes.
Comparative Example C1
467MP ADHESIVE TRANSFER TAPE (2.3 mil, 58.4 micrometers) was
laminated to HOSTAPHAN 3SAB PET.
Examples 30-39 and C1 were tested according to Test Method 2 (TM2)
and Test Method 3 (TM3).
TABLE-US-00007 TABLE 6 Properties of HBFs as a part of 2 layer
constructions RT Peel RT Peel Adhesion with Adhesion Heat (oz/in,
Without Heat Crosslinker Crosslinker N/dm) (oz/in, N/dm) Example #
Crosslinker (g) (phr) TM 2 TM 3 30 DPA 2.0 2 88.5, 96.9 6.3, 6.7 31
DPA 2.0 2 69.5, 76.1 1.1, 1.2 32 HDDA 0.1 0.1 63.6, 69.6 2.1, 2.3
33 HDDA 0.1 0.1 64.0, 70.0 1.1, 1.2 34 T1 0.1 0.1 93.1, 101.9 6.3,
6.7 35 DPA 2.0 2.0 55.6, 60.9 0.2, 0.22 36 T1 0.1 0.1 122.3, 133.9
0.4, 0.44 37 TMPDE 1.0 1.0 46.7, 51.1 0.2, 0.22 38 DVTD 1.0 1.0
63.7, 69.7 0.2, 0.22 39 DPA 2.9 2.9 40.7, 44.5 0.1, 0.11 C1 n/a n/a
n/a 127.8, 139.9 67.0, 73.3 n/a--not applicable
Heat Bondable Films Made with B30HH in 2 Layer Film
Constructions
Examples 40-42
The base formulation was made by combining 540 grams (81.8 wt. %)
of IOA, 60 grams (9.1 wt. %) of AA, 60 grams (9.1 wt. %) of B30HH,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Tapes were made by combining 100 grams of base
formulation and a quantity of crosslinker according to Table 7 in a
smaller jar, rolling overnight, coating onto HOSTAPHAN 3SAB primed
PET at 2 mil (50.8 micrometer) thickness, and curing under a
nitrogen atmosphere with 559 mJ/cm.sup.2 of UV A light over 2
minutes.
Examples 43-45
The base formulation was made by combining 540 grams (79.4 wt. %)
of IOA, 60 grams (8.8 wt. %) of AA, 78 grams (11.5 wt. %) of B30HH,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar and
mixing with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Tapes were made by combining 100 grams of base
formulation and a quantity of crosslinker according to Table 7 in a
smaller jar, rolling overnight, coating onto HOSTAPHAN 3SAB primed
PET at 2 mil (50.8 micrometer) thickness, and curing under a
nitrogen atmosphere with 559 mJ/cm.sup.2 of UV A light over 2
minutes.
Examples 40-45 were tested according to Test Method 2 (TM2) and
Test Method 3 (TM3).
TABLE-US-00008 TABLE 7 Properties of HBFs made with B30HH as a part
of 2 layer constructions RT Peel RT Peel Adhesion with Adhesion
without Crosslinker Crosslinker Heat (oz/in, Heat (oz/in, Example #
Crosslinker (g) (phr) N/dm) TM2 N/dm) TM3 40 DPA 2.0 2 52.5, 57.5
1.6, 1.8 41 HDDA 0.1 0.1 49.9, 54.6 0.8, 0.9 42 T1 0.1 0.1 86.3,
94.5 12.4, 13.6 43 DPA 2.0 2.0 24.0, 26.3 0.6, 0.7 44 HDDA 0.1 0.1
34.4, 37.7 0.5, 0.55 45 T1 0.1 0.1 92.8, 101.6 4.8, 5.3
Example 42 was also tested according to Test Method 4 and was found
to have a tensile storage modulus (E') of 16.5 MPa.
Heat Bondable Films Made with CAP in 2 Layer Film Constructions
Control Example 46
The base formulation was made by combining 270 g (81.8 wt. %) of
IOA, 30 g (9.1 wt. %) of AA, 30 g (9.1 wt. %) of CAP, and 2.1 g
(0.32 phr) of IRGACURE 651 in a glass quart jar. Solution was mixed
with a NETZSCH MODEL 50 DISPERSATOR for 30 minutes at 3000 RPM, and
then rolled for one week. Solution was not homogeneous or clear and
was not tested further.
Control Examples 47 and 48
The base formulation was made by combining 270 grams (75.0 wt. %)
of IOA, 30 grams (8.3 wt. %) of AA, 30 grams (8.3 wt. %) of HBA, 30
grams (8.3 wt. %) of CAP, and 1.15 gram (0.32 phr) of IRGACURE 651
in a glass quart jar and mixing with a NETZSCH MODEL 50 DISPERSATOR
until clear and homogeneous. Tapes were made by combining 100 grams
of base formulation and a quantity of crosslinker according to
Table 8 in a smaller jar, rolling overnight, coating onto HOSTAPHAN
3SAB primed PET at 2 mil (50.8 micrometer) thickness, and curing
under a nitrogen atmosphere with 559 mJ/cm.sup.2 of UV A light over
2 minutes.
Examples 47 and 48 were Tested According to Test Method 2.
TABLE-US-00009 TABLE 8 Properties of HBFs made with CAP as a part
of 2 layer constructions RT Peel Adhesion Crosslinker Crosslinker
with Heat (oz/in, Example # Crosslinker (g) (phr) N/dm) TM2 47 DPA
2.0 2 0.3, 0.33 48 HDDA 0.1 0.1 0.3, 0.33
Heat Bondable Films Made with PCL
Control Example 49
The base formulation was made by combining 270 grams (81.8 wt. %)
of IOA, 30 grams (9.1 wt. %) of AA, 30 grams (9.1 wt. %) of PCL,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar.
Solution was mixed with a NETZSCH MODEL 50 DISPERSATOR for 30
minutes at 3000 RPM, and then rolled for one week. Solution was not
homogeneous or clear and was not tested further.
Control Example 50
The base formulation was made by combining 270 grams (75.0 wt. %)
of IOA, 30 grams (8.3 wt. %) of AA, 30 grams (8.3 wt. %) of HBA, 30
grams (8.3 wt. %) of PCL, and 1.15 gram (0.32 phr) of IRGACURE 651
in a glass quart jar. Solution was mixed with a NETZSCH MODEL 50
DISPERSATOR for 30 minutes at 3000 RPM, and then rolled for one
week. Solution was not homogeneous or clear and was not tested
further.
Heat Bondable Films Made with PVP
Control Example 51
The base formulation was made by combining 270 grams (81.8 wt. %)
of IOA, 30 grams (9.1 wt. %) of AA, 30 grams (9.1 wt. %) of PVP,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar.
Solution was mixed with a NETZSCH MODEL 50 DISPERSATOR for 30
minutes at 3000 RPM, and then rolled for one week. Solution was not
homogeneous or clear and was not tested further.
Control Example 52
The base formulation was made by combining 270 grams (75.0 wt. %)
of IOA, 30 grams (8.3 wt. %) of AA, 30 grams (8.3 wt. %) of HBA, 30
grams (8.3 wt. %) of PVP, and 1.15 gram (0.32 phr) of IRGACURE 651
in a glass quart jar. Solution was mixed with a NETZSCH MODEL 50
DISPERSATOR for 30 minutes at 3000 RPM, and then rolled for one
week. Solution was not homogeneous or clear and was not tested
further.
Heat Bondable Films Made with PVAc
Control Example 53
The base formulation was made by combining 270 grams (81.8 wt. %)
of IOA, 30 grams (9.1 wt. %) of AA, 30 grams (9.1 wt. %) of PVAc,
and 2.1 grams (0.32 phr) of IRGACURE 651 in a glass quart jar.
Solution was mixed with a NETZSCH MODEL 50 DISPERSATOR for 30
minutes at 3000 RPM, and then rolled for one week. Solution was not
homogeneous or clear and was not tested further.
Control Example 54
The base formulation was made by combining 270 grams (75.0 wt. %)
of IOA, 30 grams (8.3 wt. %) of AA, 30 grams (8.3 wt. %) of HBA, 30
grams (8.3 wt. %) of PVAc, and 1.15 gram (0.32 phr) of IRGACURE 651
in a glass quart jar. Solution was mixed with a NETZSCH MODEL 50
DISPERSATOR for 30 minutes at 3000 RPM, and then rolled for one
week. Solution could be made clear and homogeneous with gentle
heating. Solution was allowed to cool to room temperature, and
became hazy and unhomogeneous as it cooled. Solution was not tested
further.
Examples 55-56
Mixtures of monomers, PVB polymer, and other components were added
to quart jars. The jars and contents were placed in a MAX 20 WHITE
SPEEDMIXER (available from FleckTek, Inc., Landrum, S.C.) and mixed
at 3500 RPM for 1 minute. The mixture was degassed at -20 inches of
mercury (-6.8 kPa) for 5 minutes.
IRG 651 photoinitiator in an amount ranging from about 0.15 to 0.25
wt-% was added. The mixtures of Examples 1-11 were coated at a
thickness ranging from about 1.5 to 12 mils between untreated PET
liners and under a nitrogen atmosphere cured by exposure to a UV-A
light source having a UV-A maximum in the range of 350-400 nm for
228 seconds. The total energy was measured using a Powermap.TM.
radiometer equipped with a low intensity sensing head (available
from EIT Inc., Sterling, Va.) and was 1824 mJ/cm.sup.2 for each of
these examples.
TABLE-US-00010 High Tg Low Tg Monomer Nitrogen Polar PVB Ex.
Monomer IBOA Monomer Monomer B60H Crosslinker 55 2-EHA 23.6 NVP
CD9055 19.7 CN963B80 31.5 23.6 0.2 1.1 56 2-EHA 3.2 NVP AA 15.4
CN963B80 23.0 15.4 11.6 2.0 HEA Desmodur 25.0 N3800 4.4
The composition of Example 56 contained 96 wt-% of the
(meth)acrylic polymer having the wt-% of polymerized units
specified in that table and 13 wt-% TiO.sub.2.
The films were subjected to DSC as well as Tensile Strength and
Elongation at Break testing, as previously described. The results
are reported as follows:
TABLE-US-00011 Tensile Strength Elongation Example Tg (.degree. C.)
(MPa) at Break 55 26.8 23.7 191 56 26.4 20.7 139
Examples 55 and 56 are illustrative films that can be utilized as a
replacement for polyvinyl chloride films and are not heat bondable
at the conditions previously described.
Heat Bondable Films Made with Fumed Silica
Examples 57-58
Formulations 57 and 58 were made by combining 241.8 grams (80.6 wt.
%) of IOA, 27 grams (9.0 wt. %) of AA, 31.2 grams (10.4 wt. %) of
B60HH, 6 grams (2.0 wt. %) DPA, 1.0 grams (0.33 phr) of IRGACURE
651, and a quantity of fumed silica according to Table 12 were
placed in a glass quart jar and mixed with a NETZSCH MODEL 50
DISPERSATOR until clear and homogeneous. Tapes 57 and 58 were
coated onto a release liner at 2 mil (50.8 micrometer) thickness,
and cured under a nitrogen atmosphere with 529 mJ/cm.sup.2 of UV A
light over 2 minutes.
Examples 57 and 58 were tested according to Test Methods 1, 4, and
5.
TABLE-US-00012 TABLE 12 Properties of HBFs with fumed silica RT
Peel 70.degree. C. Peel Fumed Fumed Adhesion Adhesion E' at Example
silica Silica (lbf/in, (lbf/in, 25.degree. C. Tg # (g) (wt. %)
kg/cm) kg/cm) (MPa) (.degree. C.) 57 5.0 1.5 3.9, 0.7 4.5, 0.8 36.8
-38.7 58 15.0 5.0 2.0, 0.4 4.3, 0.8 44.4 -37.7
Heat Bondable Films Made with NNDMA
Examples 59-60
Formulation 59 was made by combining 241.8 grams (80.6 wt. %) of
IOA, 27 grams (9.0 wt. %) of NNDMA, 31.2 grams (10.4 wt. %) of
B60HH, 6 grams (2.0 wt. %) DPA, and 1.0 grams (0.33 phr) of
IRGACURE 651 were placed in a glass quart jar and mixed with a
NETZSCH MODEL 50 DISPERSATOR until clear and homogeneous. Tape 59
was coated onto a release liner at 2 mil (50.8 micrometer)
thickness, and cured under a nitrogen atmosphere with 529
mJ/cm.sup.2 of UV A light over 2 minutes.
Formulation 60 was made by combining 238.2 grams (79.6 wt. %) of
IOA, 15 grams (5.0 wt. %) of NNDMA, 15 grams (5 wt. %) AA, 31.2
grams (10.4 wt. %) of B60HH, 6 grams (2.0 wt. %) DPA, and 1.0 grams
(0.33 phr) of IRGACURE 651 were placed in a glass quart jar and
mixed with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Tape 60 was coated onto a release liner at 2 mil (50.8
micrometer) thickness, and cured under a nitrogen atmosphere with
529 mJ/cm.sup.2 of UV A light over 2 minutes.
Examples 59 and 60 were tested according to Test Methods 1, 4, and
5.
TABLE-US-00013 TABLE 13 Properties of HBFs with NNDMA RT Peel
70.degree. C. Peel E' at Adhesion Adhesion 25.degree. C. Tg Example
# (lbf/in, kg/cm) (lbf/in, kg/cm) (MPa) (.degree. C.) 59 0.9, 0.2
1.9, 0.3 42.0 -42.5 60 1.5, 0.3 1.6, 0.3 50.5 -40.5
Heat Bondable Films Made with IBOA
Example 61
Formulation 61 was made by combining 241.8 grams (80.6 wt. %) of
IOA, 27 grams (9.0 wt. %) of IBOA, 27 grams (9 wt. %) of AA, 31.2
grams (10.4 wt. %) of B60HH, 6 grams (2.0 wt. %) DPA, and 1.0 grams
(0.33 phr) of IRGACURE 651 were placed in a glass quart jar and
mixed with a NETZSCH MODEL 50 DISPERSATOR until clear and
homogeneous. Tape 61 was coated onto a release liner at 2 mil (50.8
micrometer) thickness, and cured under a nitrogen atmosphere with
529 mJ/cm.sup.2 of UV A light over 2 minutes.
Example 61 were tested according to Test Methods 1, 4, and 5.
TABLE-US-00014 TABLE 14 Properties of HBFs with IBOA RT Peel
70.degree. C. Peel E' at Adhesion Adhesion 25.degree. C. Tg Example
# (lbf/in, kg/cm) (lbf/in, kg/cm) (MPa) (.degree. C.) 61 3.2, 0.6
3.8, 0.7 36.0 -32.7
Heat Bondable Films Made with EHA
Examples 62-63
Formulation 62 was made by combining 1200 grams (80.0 wt. %) of
EHA, 150 grams (10.0 wt. %) of AA, 150 grams (10.0 wt. %) of B30HH,
30 grams (2.0 wt. %) DPA, and 4.46 grams (0.33 phr) of IRGACURE 651
were placed in a glass gallon jar and mixed with a NETZSCH MODEL 50
DISPERSATOR until clear and homogeneous. Tape 62 was coated onto a
release liner at 2 mil (50.8 micrometer) thickness, and cured under
a nitrogen atmosphere with 565 mJ/cm.sup.2 of UV A light over 2
minutes.
Formulation 63 was made by combining 1200 grams (80.0 wt. %) of
EHA, 150 grams (10.0 wt. %) of AA, 150 grams (10.0 wt. %) of B60HH,
30 grams (2.0 wt. %) DPA, and 4.46 grams (0.33 phr) of IRGACURE 651
were placed in a glass gallon jar and mixed with a NETZSCH MODEL 50
DISPERSATOR until clear and homogeneous. Tape 63 was coated onto a
release liner at 2 mil (50.8 micrometer) thickness, and cured under
a nitrogen atmosphere with 565 mJ/cm.sup.2 of UV A light over 2
minutes.
Examples 62 and 63 were tested according to Test Methods 1, 4, and
5.
TABLE-US-00015 TABLE 14 Properties of HBFs with EHA RT Peel
70.degree. C. Peel E' at Adhesion Adhesion 25.degree. C. Tg Example
# PVB Used (lbf/in, kg/cm) (lbf/in, kg/cm) (MPa) (.degree. C.) 62
B30HH 9.6, 1.7 3.0, 0.5 37.8 -47.0 63 B60HH 4.3, 0.8 3.0, 0.5 35.3
-44.3
* * * * *
References